id stringlengths 24 24 | title stringlengths 3 59 | context stringlengths 151 3.71k | question stringlengths 12 217 | answers dict |
|---|---|---|---|---|
572e88f303f9891900756747 | Railway_electrification_system | In comparison to the principal alternative, the diesel engine, electric railways offer substantially better energy efficiency, lower emissions and lower operating costs. Electric locomotives are usually quieter, more powerful, and more responsive and reliable than diesels. They have no local emissions, an important adv... | What do some electric traction systems provide? | {
"text": [
"regenerative braking"
],
"answer_start": [
394
]
} |
572e88f303f9891900756748 | Railway_electrification_system | In comparison to the principal alternative, the diesel engine, electric railways offer substantially better energy efficiency, lower emissions and lower operating costs. Electric locomotives are usually quieter, more powerful, and more responsive and reliable than diesels. They have no local emissions, an important adv... | What type of fuel do diesel locomotives use? | {
"text": [
"petroleum"
],
"answer_start": [
597
]
} |
572e88f303f9891900756749 | Railway_electrification_system | In comparison to the principal alternative, the diesel engine, electric railways offer substantially better energy efficiency, lower emissions and lower operating costs. Electric locomotives are usually quieter, more powerful, and more responsive and reliable than diesels. They have no local emissions, an important adv... | What is one of the sources electricity is being generated from? | {
"text": [
"geothermal"
],
"answer_start": [
771
]
} |
572e8e0fcb0c0d14000f1290 | Railway_electrification_system | Disadvantages of electric traction include high capital costs that may be uneconomic on lightly trafficked routes; a relative lack of flexibility since electric trains need electrified tracks or onboard supercapacitors and charging infrastructure at stations; and a vulnerability to power interruptions. Different region... | What issue can complicate electric railway service? | {
"text": [
"different supply voltages and frequencies,"
],
"answer_start": [
330
]
} |
572e8e0fcb0c0d14000f1291 | Railway_electrification_system | Disadvantages of electric traction include high capital costs that may be uneconomic on lightly trafficked routes; a relative lack of flexibility since electric trains need electrified tracks or onboard supercapacitors and charging infrastructure at stations; and a vulnerability to power interruptions. Different region... | What is a safety hazard to track workers? | {
"text": [
"voltages on contact wires"
],
"answer_start": [
519
]
} |
572e8e0fcb0c0d14000f1292 | Railway_electrification_system | Disadvantages of electric traction include high capital costs that may be uneconomic on lightly trafficked routes; a relative lack of flexibility since electric trains need electrified tracks or onboard supercapacitors and charging infrastructure at stations; and a vulnerability to power interruptions. Different region... | What is a safer alternative to third rails? | {
"text": [
"Overhead wires"
],
"answer_start": [
627
]
} |
572e8e0fcb0c0d14000f1293 | Railway_electrification_system | Disadvantages of electric traction include high capital costs that may be uneconomic on lightly trafficked routes; a relative lack of flexibility since electric trains need electrified tracks or onboard supercapacitors and charging infrastructure at stations; and a vulnerability to power interruptions. Different region... | Why overhead wires are not being widely used? | {
"text": [
"considered unsightly."
],
"answer_start": [
689
]
} |
572e8f7803f98919007567a1 | Railway_electrification_system | Railways must operate at variable speeds. Until the mid 1980s this was only practical with the brush-type DC motor, although such DC can be supplied from an AC catenary via on-board electric power conversion. Since such conversion was not well developed in the late 19th century and early 20th century, most early electr... | What is speed limit for railways? | {
"text": [
"variable speeds"
],
"answer_start": [
25
]
} |
572e8f7803f98919007567a2 | Railway_electrification_system | Railways must operate at variable speeds. Until the mid 1980s this was only practical with the brush-type DC motor, although such DC can be supplied from an AC catenary via on-board electric power conversion. Since such conversion was not well developed in the late 19th century and early 20th century, most early electr... | Why is DC motor being used more than AC type? | {
"text": [
"conversion was not well developed"
],
"answer_start": [
220
]
} |
572e8f7803f98919007567a3 | Railway_electrification_system | Railways must operate at variable speeds. Until the mid 1980s this was only practical with the brush-type DC motor, although such DC can be supplied from an AC catenary via on-board electric power conversion. Since such conversion was not well developed in the late 19th century and early 20th century, most early electr... | What are two types of railway transportation still use DC motor? | {
"text": [
"rapid transit (subways) and trams"
],
"answer_start": [
375
]
} |
572f2607947a6a140053c7dc | Railway_electrification_system | Motors have very little room for electrical insulation so they generally have low voltage ratings. Because transformers (prior to the development of power electronics) cannot step down DC voltages, trains were supplied with a relatively low DC voltage that the motors can use directly. The most common DC voltages are li... | Why do motors have little space for insulation? | {
"text": [
"low voltage ratings"
],
"answer_start": [
78
]
} |
572f2607947a6a140053c7dd | Railway_electrification_system | Motors have very little room for electrical insulation so they generally have low voltage ratings. Because transformers (prior to the development of power electronics) cannot step down DC voltages, trains were supplied with a relatively low DC voltage that the motors can use directly. The most common DC voltages are li... | What is most common volatage range used by railway system? | {
"text": [
"below 1 kV"
],
"answer_start": [
409
]
} |
572f2607947a6a140053c7de | Railway_electrification_system | Motors have very little room for electrical insulation so they generally have low voltage ratings. Because transformers (prior to the development of power electronics) cannot step down DC voltages, trains were supplied with a relatively low DC voltage that the motors can use directly. The most common DC voltages are li... | Why 1kV voltage is almost always used by rail systems? | {
"text": [
"safety reasons"
],
"answer_start": [
424
]
} |
572f2607947a6a140053c7df | Railway_electrification_system | Motors have very little room for electrical insulation so they generally have low voltage ratings. Because transformers (prior to the development of power electronics) cannot step down DC voltages, trains were supplied with a relatively low DC voltage that the motors can use directly. The most common DC voltages are li... | Which system uses higher voltages? | {
"text": [
"overhead wires"
],
"answer_start": [
445
]
} |
572f2607947a6a140053c7e0 | Railway_electrification_system | Motors have very little room for electrical insulation so they generally have low voltage ratings. Because transformers (prior to the development of power electronics) cannot step down DC voltages, trains were supplied with a relatively low DC voltage that the motors can use directly. The most common DC voltages are li... | Is "low" voltage used by trains safe for people? | {
"text": [
"lethal"
],
"answer_start": [
560
]
} |
572f2836b2c2fd1400567f47 | Railway_electrification_system | There has, however, been interest among railroad operators in returning to DC use at higher voltages than previously used. At the same voltage, DC often has less loss than AC, and for this reason high-voltage direct current is already used on some bulk power transmission lines. DC avoids the electromagnetic radiation i... | What type of electric power garantees lesser loss? | {
"text": [
"DC"
],
"answer_start": [
144
]
} |
572f2836b2c2fd1400567f48 | Railway_electrification_system | There has, however, been interest among railroad operators in returning to DC use at higher voltages than previously used. At the same voltage, DC often has less loss than AC, and for this reason high-voltage direct current is already used on some bulk power transmission lines. DC avoids the electromagnetic radiation i... | Which type of supply for electric motors creates electromagnetic radiation? | {
"text": [
"AC"
],
"answer_start": [
172
]
} |
572f2836b2c2fd1400567f49 | Railway_electrification_system | There has, however, been interest among railroad operators in returning to DC use at higher voltages than previously used. At the same voltage, DC often has less loss than AC, and for this reason high-voltage direct current is already used on some bulk power transmission lines. DC avoids the electromagnetic radiation i... | What can electromagnetic radiation interfere with? | {
"text": [
"signalling and communications"
],
"answer_start": [
390
]
} |
572f2836b2c2fd1400567f4a | Railway_electrification_system | There has, however, been interest among railroad operators in returning to DC use at higher voltages than previously used. At the same voltage, DC often has less loss than AC, and for this reason high-voltage direct current is already used on some bulk power transmission lines. DC avoids the electromagnetic radiation i... | Which type of power does require three-phase transmission? | {
"text": [
"AC"
],
"answer_start": [
632
]
} |
572f2836b2c2fd1400567f4b | Railway_electrification_system | There has, however, been interest among railroad operators in returning to DC use at higher voltages than previously used. At the same voltage, DC often has less loss than AC, and for this reason high-voltage direct current is already used on some bulk power transmission lines. DC avoids the electromagnetic radiation i... | Where was an experimental 6kV DC railway built? | {
"text": [
"the Soviet Union"
],
"answer_start": [
1380
]
} |
572f2b31947a6a140053c7e6 | Railway_electrification_system | 1,500 V DC is used in the Netherlands, Japan, Republic Of Indonesia, Hong Kong (parts), Republic of Ireland, Australia (parts), India (around the Mumbai area alone, has been converted to 25 kV AC like the rest of India), France (also using 25 kV 50 Hz AC), New Zealand (Wellington) and the United States (Chicago area on... | What is most common voltage for DC supply? | {
"text": [
"1,500 V"
],
"answer_start": [
0
]
} |
572f2b31947a6a140053c7e7 | Railway_electrification_system | 1,500 V DC is used in the Netherlands, Japan, Republic Of Indonesia, Hong Kong (parts), Republic of Ireland, Australia (parts), India (around the Mumbai area alone, has been converted to 25 kV AC like the rest of India), France (also using 25 kV 50 Hz AC), New Zealand (Wellington) and the United States (Chicago area on... | How many narrow-gauge lines in Slovakia? | {
"text": [
"two"
],
"answer_start": [
415
]
} |
572f2b31947a6a140053c7e8 | Railway_electrification_system | 1,500 V DC is used in the Netherlands, Japan, Republic Of Indonesia, Hong Kong (parts), Republic of Ireland, Australia (parts), India (around the Mumbai area alone, has been converted to 25 kV AC like the rest of India), France (also using 25 kV 50 Hz AC), New Zealand (Wellington) and the United States (Chicago area on... | What railway line is DC being used in Portugal? | {
"text": [
"the Cascais Line"
],
"answer_start": [
505
]
} |
572f2b31947a6a140053c7e9 | Railway_electrification_system | 1,500 V DC is used in the Netherlands, Japan, Republic Of Indonesia, Hong Kong (parts), Republic of Ireland, Australia (parts), India (around the Mumbai area alone, has been converted to 25 kV AC like the rest of India), France (also using 25 kV 50 Hz AC), New Zealand (Wellington) and the United States (Chicago area on... | Where in India line has been converted to AC? | {
"text": [
"Mumbai area"
],
"answer_start": [
146
]
} |
572f2ce3a23a5019007fc4b3 | Railway_electrification_system | 3 kV DC is used in Belgium, Italy, Spain, Poland, the northern Czech Republic, Slovakia, Slovenia, South Africa, Chile, and former Soviet Union countries (also using 25 kV 50 Hz AC). It was formerly used by the Milwaukee Road from Harlowton, Montana to Seattle-Tacoma, across the Continental Divide and including extensi... | What voltage is being used in railway system of South Africa and Chile? | {
"text": [
"3 kV DC"
],
"answer_start": [
0
]
} |
572f2ce3a23a5019007fc4b4 | Railway_electrification_system | 3 kV DC is used in Belgium, Italy, Spain, Poland, the northern Czech Republic, Slovakia, Slovenia, South Africa, Chile, and former Soviet Union countries (also using 25 kV 50 Hz AC). It was formerly used by the Milwaukee Road from Harlowton, Montana to Seattle-Tacoma, across the Continental Divide and including extensi... | Besides using 3kV DC what other power type is used in the former Soviet Union countries? | {
"text": [
"25 kV 50 Hz AC"
],
"answer_start": [
166
]
} |
572f2ce3a23a5019007fc4b5 | Railway_electrification_system | 3 kV DC is used in Belgium, Italy, Spain, Poland, the northern Czech Republic, Slovakia, Slovenia, South Africa, Chile, and former Soviet Union countries (also using 25 kV 50 Hz AC). It was formerly used by the Milwaukee Road from Harlowton, Montana to Seattle-Tacoma, across the Continental Divide and including extensi... | What was New Jersey Transit called before? | {
"text": [
"Western Railroad"
],
"answer_start": [
391
]
} |
572f2ce3a23a5019007fc4b6 | Railway_electrification_system | 3 kV DC is used in Belgium, Italy, Spain, Poland, the northern Czech Republic, Slovakia, Slovenia, South Africa, Chile, and former Soviet Union countries (also using 25 kV 50 Hz AC). It was formerly used by the Milwaukee Road from Harlowton, Montana to Seattle-Tacoma, across the Continental Divide and including extensi... | What does the railway system of US use DC or AC? | {
"text": [
"AC"
],
"answer_start": [
582
]
} |
572f2eff04bcaa1900d76775 | Railway_electrification_system | Most electrification systems use overhead wires, but third rail is an option up to about 1,200 V. Third rail systems exclusively use DC distribution. The use of AC is not feasible because the dimensions of a third rail are physically very large compared with the skin depth that the alternating current penetrates to (0.... | What type is mostly used third rail or overhead wires? | {
"text": [
"overhead wires"
],
"answer_start": [
33
]
} |
572f2eff04bcaa1900d76776 | Railway_electrification_system | Most electrification systems use overhead wires, but third rail is an option up to about 1,200 V. Third rail systems exclusively use DC distribution. The use of AC is not feasible because the dimensions of a third rail are physically very large compared with the skin depth that the alternating current penetrates to (0.... | Is trird rail system being used exclusively with AC or DC ? | {
"text": [
"DC distribution"
],
"answer_start": [
133
]
} |
572f2eff04bcaa1900d76777 | Railway_electrification_system | Most electrification systems use overhead wires, but third rail is an option up to about 1,200 V. Third rail systems exclusively use DC distribution. The use of AC is not feasible because the dimensions of a third rail are physically very large compared with the skin depth that the alternating current penetrates to (0.... | What depth does the alternating current penetrate in a steel rail? | {
"text": [
"skin depth"
],
"answer_start": [
263
]
} |
572f2eff04bcaa1900d76778 | Railway_electrification_system | Most electrification systems use overhead wires, but third rail is an option up to about 1,200 V. Third rail systems exclusively use DC distribution. The use of AC is not feasible because the dimensions of a third rail are physically very large compared with the skin depth that the alternating current penetrates to (0.... | What is physically more compact tird rail or overhead wires? | {
"text": [
"Third rail"
],
"answer_start": [
465
]
} |
572f2eff04bcaa1900d76779 | Railway_electrification_system | Most electrification systems use overhead wires, but third rail is an option up to about 1,200 V. Third rail systems exclusively use DC distribution. The use of AC is not feasible because the dimensions of a third rail are physically very large compared with the skin depth that the alternating current penetrates to (0.... | What is more prefferable for subway lines? | {
"text": [
"Third rail"
],
"answer_start": [
465
]
} |
572f3099a23a5019007fc4c5 | Railway_electrification_system | DC systems (especially third-rail systems) are limited to relatively low voltages and this can limit the size and speed of trains and cannot use low-level platform and also limit the amount of air-conditioning that the trains can provide. This may be a factor favouring overhead wires and high-voltage AC, even for urban... | Why DC system can effect the speed of trains? | {
"text": [
"low voltages"
],
"answer_start": [
69
]
} |
572f3099a23a5019007fc4c6 | Railway_electrification_system | DC systems (especially third-rail systems) are limited to relatively low voltages and this can limit the size and speed of trains and cannot use low-level platform and also limit the amount of air-conditioning that the trains can provide. This may be a factor favouring overhead wires and high-voltage AC, even for urban... | Can DC systems use low-level platform? | {
"text": [
"cannot"
],
"answer_start": [
134
]
} |
572f3099a23a5019007fc4c7 | Railway_electrification_system | DC systems (especially third-rail systems) are limited to relatively low voltages and this can limit the size and speed of trains and cannot use low-level platform and also limit the amount of air-conditioning that the trains can provide. This may be a factor favouring overhead wires and high-voltage AC, even for urban... | Besides speed and size what else the low voltage of DC system can effect? | {
"text": [
"air-conditioning"
],
"answer_start": [
193
]
} |
572f3099a23a5019007fc4c8 | Railway_electrification_system | DC systems (especially third-rail systems) are limited to relatively low voltages and this can limit the size and speed of trains and cannot use low-level platform and also limit the amount of air-conditioning that the trains can provide. This may be a factor favouring overhead wires and high-voltage AC, even for urban... | What is the speed limit for third rail system trains? | {
"text": [
"160 km/h"
],
"answer_start": [
410
]
} |
572f3099a23a5019007fc4c9 | Railway_electrification_system | DC systems (especially third-rail systems) are limited to relatively low voltages and this can limit the size and speed of trains and cannot use low-level platform and also limit the amount of air-conditioning that the trains can provide. This may be a factor favouring overhead wires and high-voltage AC, even for urban... | What can become unreliable if the speed exceeds the limit of 100 mph for DC system trains? | {
"text": [
"contact between the shoe and the rail"
],
"answer_start": [
454
]
} |
572f3315b2c2fd1400567f77 | Railway_electrification_system | Some street trams (streetcars) used conduit third-rail current collection. The third rail was below street level. The tram picked up the current through a plough (U.S. "plow") accessed through a narrow slot in the road. In the United States, much (though not all) of the former streetcar system in Washington, D.C. (disc... | What is the other name for the street trams? | {
"text": [
"streetcars"
],
"answer_start": [
19
]
} |
572f3315b2c2fd1400567f78 | Railway_electrification_system | Some street trams (streetcars) used conduit third-rail current collection. The third rail was below street level. The tram picked up the current through a plough (U.S. "plow") accessed through a narrow slot in the road. In the United States, much (though not all) of the former streetcar system in Washington, D.C. (disc... | Where is third rail situated in the street trams system? | {
"text": [
"below street level"
],
"answer_start": [
94
]
} |
572f3315b2c2fd1400567f79 | Railway_electrification_system | Some street trams (streetcars) used conduit third-rail current collection. The third rail was below street level. The tram picked up the current through a plough (U.S. "plow") accessed through a narrow slot in the road. In the United States, much (though not all) of the former streetcar system in Washington, D.C. (disc... | What area in US discontinued using overhead wires for streetcars in 1962? | {
"text": [
"Washington, D.C."
],
"answer_start": [
298
]
} |
572f3315b2c2fd1400567f7a | Railway_electrification_system | Some street trams (streetcars) used conduit third-rail current collection. The third rail was below street level. The tram picked up the current through a plough (U.S. "plow") accessed through a narrow slot in the road. In the United States, much (though not all) of the former streetcar system in Washington, D.C. (disc... | What external and weather factors can effect conduit slot? | {
"text": [
"leaves and snow"
],
"answer_start": [
1171
]
} |
572f3315b2c2fd1400567f7b | Railway_electrification_system | Some street trams (streetcars) used conduit third-rail current collection. The third rail was below street level. The tram picked up the current through a plough (U.S. "plow") accessed through a narrow slot in the road. In the United States, much (though not all) of the former streetcar system in Washington, D.C. (disc... | What are the main reasons the conduit lines were converted to overhead wire system? | {
"text": [
"cost and operating efficiency"
],
"answer_start": [
1507
]
} |
572f3f3404bcaa1900d767c5 | Railway_electrification_system | A new approach to avoiding overhead wires is taken by the "second generation" tram/streetcar system in Bordeaux, France (entry into service of the first line in December 2003; original system discontinued in 1958) with its APS (alimentation par sol – ground current feed). This involves a third rail which is flush with ... | What year the "second generation" of tram system began to operate in France? | {
"text": [
"2003"
],
"answer_start": [
170
]
} |
572f3f3404bcaa1900d767c6 | Railway_electrification_system | A new approach to avoiding overhead wires is taken by the "second generation" tram/streetcar system in Bordeaux, France (entry into service of the first line in December 2003; original system discontinued in 1958) with its APS (alimentation par sol – ground current feed). This involves a third rail which is flush with ... | When was the original system discontinued? | {
"text": [
"1958"
],
"answer_start": [
208
]
} |
572f3f3404bcaa1900d767c7 | Railway_electrification_system | A new approach to avoiding overhead wires is taken by the "second generation" tram/streetcar system in Bordeaux, France (entry into service of the first line in December 2003; original system discontinued in 1958) with its APS (alimentation par sol – ground current feed). This involves a third rail which is flush with ... | How is the circuit of the third rail divided? | {
"text": [
"energized segment"
],
"answer_start": [
548
]
} |
572f3f3404bcaa1900d767c8 | Railway_electrification_system | A new approach to avoiding overhead wires is taken by the "second generation" tram/streetcar system in Bordeaux, France (entry into service of the first line in December 2003; original system discontinued in 1958) with its APS (alimentation par sol – ground current feed). This involves a third rail which is flush with ... | Does energized segment of third rail pose the threat to pedestrians if uncovered? | {
"text": [
"no danger"
],
"answer_start": [
700
]
} |
572f40f1b2c2fd1400567f9f | Railway_electrification_system | The London Underground in England is one of the few networks that uses a four-rail system. The additional rail carries the electrical return that, on third rail and overhead networks, is provided by the running rails. On the London Underground, a top-contact third rail is beside the track, energized at +420v DC, and a ... | What type of system does London Underground use? | {
"text": [
"four-rail system"
],
"answer_start": [
73
]
} |
572f40f1b2c2fd1400567fa0 | Railway_electrification_system | The London Underground in England is one of the few networks that uses a four-rail system. The additional rail carries the electrical return that, on third rail and overhead networks, is provided by the running rails. On the London Underground, a top-contact third rail is beside the track, energized at +420v DC, and a ... | What is the purpose of the forth rail? | {
"text": [
"carries the electrical return"
],
"answer_start": [
111
]
} |
572f40f1b2c2fd1400567fa1 | Railway_electrification_system | The London Underground in England is one of the few networks that uses a four-rail system. The additional rail carries the electrical return that, on third rail and overhead networks, is provided by the running rails. On the London Underground, a top-contact third rail is beside the track, energized at +420v DC, and a ... | What is the volatage surge of the third rail of London Underground system? | {
"text": [
"+420v DC"
],
"answer_start": [
304
]
} |
572f40f1b2c2fd1400567fa2 | Railway_electrification_system | The London Underground in England is one of the few networks that uses a four-rail system. The additional rail carries the electrical return that, on third rail and overhead networks, is provided by the running rails. On the London Underground, a top-contact third rail is beside the track, energized at +420v DC, and a ... | What is the voltage of the return rail? | {
"text": [
"−210v DC"
],
"answer_start": [
394
]
} |
572f40f1b2c2fd1400567fa3 | Railway_electrification_system | The London Underground in England is one of the few networks that uses a four-rail system. The additional rail carries the electrical return that, on third rail and overhead networks, is provided by the running rails. On the London Underground, a top-contact third rail is beside the track, energized at +420v DC, and a ... | Where was the system similar to London Underground used as well? | {
"text": [
"Milan"
],
"answer_start": [
772
]
} |
572f42c2947a6a140053c81e | Railway_electrification_system | The key advantage of the four-rail system is that neither running rail carries any current. This scheme was introduced because of the problems of return currents, intended to be carried by the earthed (grounded) running rail, flowing through the iron tunnel linings instead. This can cause electrolytic damage and even a... | What is the crucial advantage of four-rail system? | {
"text": [
"running rail carries any current"
],
"answer_start": [
58
]
} |
572f42c2947a6a140053c81f | Railway_electrification_system | The key advantage of the four-rail system is that neither running rail carries any current. This scheme was introduced because of the problems of return currents, intended to be carried by the earthed (grounded) running rail, flowing through the iron tunnel linings instead. This can cause electrolytic damage and even a... | What danger can return currents cause? | {
"text": [
"electrolytic damage"
],
"answer_start": [
290
]
} |
572f42c2947a6a140053c820 | Railway_electrification_system | The key advantage of the four-rail system is that neither running rail carries any current. This scheme was introduced because of the problems of return currents, intended to be carried by the earthed (grounded) running rail, flowing through the iron tunnel linings instead. This can cause electrolytic damage and even a... | How did return current effect water and gas in iron pipes? | {
"text": [
"water and gas mains"
],
"answer_start": [
508
]
} |
572f42c2947a6a140053c821 | Railway_electrification_system | The key advantage of the four-rail system is that neither running rail carries any current. This scheme was introduced because of the problems of return currents, intended to be carried by the earthed (grounded) running rail, flowing through the iron tunnel linings instead. This can cause electrolytic damage and even a... | How are stray earth currents kept to a manageable levels? | {
"text": [
"by using resistors"
],
"answer_start": [
848
]
} |
572f42c2947a6a140053c822 | Railway_electrification_system | The key advantage of the four-rail system is that neither running rail carries any current. This scheme was introduced because of the problems of return currents, intended to be carried by the earthed (grounded) running rail, flowing through the iron tunnel linings instead. This can cause electrolytic damage and even a... | What insures minimal current leak during power rails instalation? | {
"text": [
"ceramic chairs"
],
"answer_start": [
993
]
} |
572f447f947a6a140053c844 | Railway_electrification_system | On tracks that London Underground share with National Rail third-rail stock (the Bakerloo and District lines both have such sections), the centre rail is connected to the running rails, allowing both types of train to operate, at a compromise voltage of 660 V. Underground trains pass from one section to the other at sp... | What is the voltage shared two types of trains UK railroad system? | {
"text": [
"660 V"
],
"answer_start": [
254
]
} |
572f447f947a6a140053c845 | Railway_electrification_system | On tracks that London Underground share with National Rail third-rail stock (the Bakerloo and District lines both have such sections), the centre rail is connected to the running rails, allowing both types of train to operate, at a compromise voltage of 660 V. Underground trains pass from one section to the other at sp... | Why some sections of Bakerloo and District lines were rewired to three-rail system? | {
"text": [
"to simplify rolling stock use"
],
"answer_start": [
568
]
} |
572f447f947a6a140053c846 | Railway_electrification_system | On tracks that London Underground share with National Rail third-rail stock (the Bakerloo and District lines both have such sections), the centre rail is connected to the running rails, allowing both types of train to operate, at a compromise voltage of 660 V. Underground trains pass from one section to the other at sp... | How did it become possible to share the voltage for different types of train? | {
"text": [
"the centre rail is connected to the running rails"
],
"answer_start": [
135
]
} |
572f4794b2c2fd1400567fc7 | Railway_electrification_system | A few lines of the Paris Métro in France operate on a four-rail power scheme because they run on rubber tyres which run on a pair of narrow roadways made of steel and, in some places, concrete. Since the tyres do not conduct the return current, the two guide rails provided outside the running 'roadways' double up as co... | Why some lines of Paris Metro have to operate on a four-rail system? | {
"text": [
"rubber tyres"
],
"answer_start": [
97
]
} |
572f4794b2c2fd1400567fc8 | Railway_electrification_system | A few lines of the Paris Métro in France operate on a four-rail power scheme because they run on rubber tyres which run on a pair of narrow roadways made of steel and, in some places, concrete. Since the tyres do not conduct the return current, the two guide rails provided outside the running 'roadways' double up as co... | What was the solution for the return current problem in Paris Metro? | {
"text": [
"two guide rails"
],
"answer_start": [
249
]
} |
572f4794b2c2fd1400567fc9 | Railway_electrification_system | A few lines of the Paris Métro in France operate on a four-rail power scheme because they run on rubber tyres which run on a pair of narrow roadways made of steel and, in some places, concrete. Since the tyres do not conduct the return current, the two guide rails provided outside the running 'roadways' double up as co... | What is required in order for the guide rails to operate properly? | {
"text": [
"a single polarity supply"
],
"answer_start": [
491
]
} |
572f4794b2c2fd1400567fca | Railway_electrification_system | A few lines of the Paris Métro in France operate on a four-rail power scheme because they run on rubber tyres which run on a pair of narrow roadways made of steel and, in some places, concrete. Since the tyres do not conduct the return current, the two guide rails provided outside the running 'roadways' double up as co... | How train is able to turn around after each completed journey? | {
"text": [
"reversing loops"
],
"answer_start": [
619
]
} |
572f4794b2c2fd1400567fcb | Railway_electrification_system | A few lines of the Paris Métro in France operate on a four-rail power scheme because they run on rubber tyres which run on a pair of narrow roadways made of steel and, in some places, concrete. Since the tyres do not conduct the return current, the two guide rails provided outside the running 'roadways' double up as co... | Why was the reversing loop created? | {
"text": [
"having to 'run around' the rest of the train"
],
"answer_start": [
783
]
} |
572f498104bcaa1900d76817 | Railway_electrification_system | An early advantage of AC is that the power-wasting resistors used in DC locomotives for speed control were not needed in an AC locomotive: multiple taps on the transformer can supply a range of voltages. Separate low-voltage transformer windings supply lighting and the motors driving auxiliary machinery. More recently,... | What was a disadvantage of DC system? | {
"text": [
"power-wasting resistors"
],
"answer_start": [
37
]
} |
572f498104bcaa1900d76818 | Railway_electrification_system | An early advantage of AC is that the power-wasting resistors used in DC locomotives for speed control were not needed in an AC locomotive: multiple taps on the transformer can supply a range of voltages. Separate low-voltage transformer windings supply lighting and the motors driving auxiliary machinery. More recently,... | How can different range of voltages be supplied for AC locomotives? | {
"text": [
"multiple taps on the transformer"
],
"answer_start": [
139
]
} |
572f498104bcaa1900d76819 | Railway_electrification_system | An early advantage of AC is that the power-wasting resistors used in DC locomotives for speed control were not needed in an AC locomotive: multiple taps on the transformer can supply a range of voltages. Separate low-voltage transformer windings supply lighting and the motors driving auxiliary machinery. More recently,... | What taps can provide lighting supply? | {
"text": [
"low-voltage transformer windings"
],
"answer_start": [
213
]
} |
572f498104bcaa1900d7681a | Railway_electrification_system | An early advantage of AC is that the power-wasting resistors used in DC locomotives for speed control were not needed in an AC locomotive: multiple taps on the transformer can supply a range of voltages. Separate low-voltage transformer windings supply lighting and the motors driving auxiliary machinery. More recently,... | What will AC/DC motor be replaced with? | {
"text": [
"three-phase induction motor"
],
"answer_start": [
450
]
} |
572f4ab9b2c2fd1400567fef | Railway_electrification_system | DC commutating electric motors, if fitted with laminated pole pieces, become universal motors because they can also operate on AC; reversing the current in both stator and rotor does not reverse the motor. But the now-standard AC distribution frequencies of 50 and 60 Hz caused difficulties with inductive reactance and ... | How can DC motor turn universal? | {
"text": [
"if fitted with laminated pole pieces"
],
"answer_start": [
32
]
} |
572f4ab9b2c2fd1400567ff0 | Railway_electrification_system | DC commutating electric motors, if fitted with laminated pole pieces, become universal motors because they can also operate on AC; reversing the current in both stator and rotor does not reverse the motor. But the now-standard AC distribution frequencies of 50 and 60 Hz caused difficulties with inductive reactance and ... | What problems did AC distribution cause? | {
"text": [
"inductive reactance and eddy current losses"
],
"answer_start": [
296
]
} |
572f4ab9b2c2fd1400567ff1 | Railway_electrification_system | DC commutating electric motors, if fitted with laminated pole pieces, become universal motors because they can also operate on AC; reversing the current in both stator and rotor does not reverse the motor. But the now-standard AC distribution frequencies of 50 and 60 Hz caused difficulties with inductive reactance and ... | How do railways try to solve the problem of inductive reactance of AC system? | {
"text": [
"low AC frequencies"
],
"answer_start": [
361
]
} |
572f4ab9b2c2fd1400567ff2 | Railway_electrification_system | DC commutating electric motors, if fitted with laminated pole pieces, become universal motors because they can also operate on AC; reversing the current in both stator and rotor does not reverse the motor. But the now-standard AC distribution frequencies of 50 and 60 Hz caused difficulties with inductive reactance and ... | How can low frequencies be obtained? | {
"text": [
"converted from utility power"
],
"answer_start": [
421
]
} |
572f4cdaa23a5019007fc501 | Railway_electrification_system | High-voltage AC overhead systems are not only for standard gauge national networks. The meter gauge Rhaetian Railway (RhB) and the neighbouring Matterhorn Gotthard Bahn (MGB) operate on 11 kV at 16.7 Hz frequency. Practice has proven that both Swiss and German 15 kV trains can operate under these lower voltages. The Rh... | How did non-standard gauge trains start to operate with high-voltage AC? | {
"text": [
"adopting the already proven RhB system."
],
"answer_start": [
556
]
} |
572f4cdaa23a5019007fc502 | Railway_electrification_system | High-voltage AC overhead systems are not only for standard gauge national networks. The meter gauge Rhaetian Railway (RhB) and the neighbouring Matterhorn Gotthard Bahn (MGB) operate on 11 kV at 16.7 Hz frequency. Practice has proven that both Swiss and German 15 kV trains can operate under these lower voltages. The Rh... | When was the first trail of RhB system tested? | {
"text": [
"1913"
],
"answer_start": [
360
]
} |
572f4ec3a23a5019007fc505 | Railway_electrification_system | In the United States, 25 Hz, a once-common industrial power frequency is used on Amtrak's 25 Hz traction power system at 12 kV on the Northeast Corridor between Washington, D.C. and New York City and on the Keystone Corridor between Harrisburg, Pennsylvania and Philadelphia. SEPTA's 25 Hz traction power system uses the... | What frequency was typically used on US Amtrak? | {
"text": [
"25 Hz"
],
"answer_start": [
22
]
} |
572f4ec3a23a5019007fc506 | Railway_electrification_system | In the United States, 25 Hz, a once-common industrial power frequency is used on Amtrak's 25 Hz traction power system at 12 kV on the Northeast Corridor between Washington, D.C. and New York City and on the Keystone Corridor between Harrisburg, Pennsylvania and Philadelphia. SEPTA's 25 Hz traction power system uses the... | What voltage does SEPTA system use? | {
"text": [
"12 kV voltage"
],
"answer_start": [
326
]
} |
572f4ec3a23a5019007fc507 | Railway_electrification_system | In the United States, 25 Hz, a once-common industrial power frequency is used on Amtrak's 25 Hz traction power system at 12 kV on the Northeast Corridor between Washington, D.C. and New York City and on the Keystone Corridor between Harrisburg, Pennsylvania and Philadelphia. SEPTA's 25 Hz traction power system uses the... | What specification is similar for both Amtrak and Septa systems? | {
"text": [
"catenary voltage"
],
"answer_start": [
496
]
} |
572f4ec3a23a5019007fc508 | Railway_electrification_system | In the United States, 25 Hz, a once-common industrial power frequency is used on Amtrak's 25 Hz traction power system at 12 kV on the Northeast Corridor between Washington, D.C. and New York City and on the Keystone Corridor between Harrisburg, Pennsylvania and Philadelphia. SEPTA's 25 Hz traction power system uses the... | When was a 11kV system of NY, New Haven and Hartford was converted to 12.5 kV? | {
"text": [
"1987"
],
"answer_start": [
1065
]
} |
572f506a04bcaa1900d76841 | Railway_electrification_system | In the UK, the London, Brighton and South Coast Railway pioneered overhead electrification of its suburban lines in London, London Bridge to Victoria being opened to traffic on 1 December 1909. Victoria to Crystal Palace via Balham and West Norwood opened in May 1911. Peckham Rye to West Norwood opened in June 1912. Fu... | When was overhead wires system being used for the first time in UK? | {
"text": [
"1 December 1909"
],
"answer_start": [
177
]
} |
572f506a04bcaa1900d76842 | Railway_electrification_system | In the UK, the London, Brighton and South Coast Railway pioneered overhead electrification of its suburban lines in London, London Bridge to Victoria being opened to traffic on 1 December 1909. Victoria to Crystal Palace via Balham and West Norwood opened in May 1911. Peckham Rye to West Norwood opened in June 1912. Fu... | What line used the overhead wire system first Victoria to Crystal Palace or Peckham Rye to West Noorwood? | {
"text": [
"Victoria to Crystal Palace"
],
"answer_start": [
194
]
} |
572f506a04bcaa1900d76843 | Railway_electrification_system | In the UK, the London, Brighton and South Coast Railway pioneered overhead electrification of its suburban lines in London, London Bridge to Victoria being opened to traffic on 1 December 1909. Victoria to Crystal Palace via Balham and West Norwood opened in May 1911. Peckham Rye to West Norwood opened in June 1912. Fu... | What was the cause of lines not being extended? | {
"text": [
"the First World War"
],
"answer_start": [
360
]
} |
572f506a04bcaa1900d76844 | Railway_electrification_system | In the UK, the London, Brighton and South Coast Railway pioneered overhead electrification of its suburban lines in London, London Bridge to Victoria being opened to traffic on 1 December 1909. Victoria to Crystal Palace via Balham and West Norwood opened in May 1911. Peckham Rye to West Norwood opened in June 1912. Fu... | What voltage was used in the two lines opened in 1925 of Southern Railway? | {
"text": [
"6.7 kV 25 Hz"
],
"answer_start": [
514
]
} |
572f52bc04bcaa1900d76849 | Railway_electrification_system | Three-phase AC railway electrification was used in Italy, Switzerland and the United States in the early twentieth century. Italy was the major user, for lines in the mountainous regions of northern Italy from 1901 until 1976. The first lines were the Burgdorf-Thun line in Switzerland (1899), and the lines of the Ferro... | What countries used three-phase AC system in the the beginning of 20th century? | {
"text": [
"Italy, Switzerland and the United States"
],
"answer_start": [
51
]
} |
572f52bc04bcaa1900d7684a | Railway_electrification_system | Three-phase AC railway electrification was used in Italy, Switzerland and the United States in the early twentieth century. Italy was the major user, for lines in the mountainous regions of northern Italy from 1901 until 1976. The first lines were the Burgdorf-Thun line in Switzerland (1899), and the lines of the Ferro... | What country was a bigger user compare to the three of them? | {
"text": [
"Italy"
],
"answer_start": [
124
]
} |
572f52bc04bcaa1900d7684b | Railway_electrification_system | Three-phase AC railway electrification was used in Italy, Switzerland and the United States in the early twentieth century. Italy was the major user, for lines in the mountainous regions of northern Italy from 1901 until 1976. The first lines were the Burgdorf-Thun line in Switzerland (1899), and the lines of the Ferro... | Where did Italy start using the AC system? | {
"text": [
"in the mountainous regions of northern Italy"
],
"answer_start": [
160
]
} |
572f52bc04bcaa1900d7684c | Railway_electrification_system | Three-phase AC railway electrification was used in Italy, Switzerland and the United States in the early twentieth century. Italy was the major user, for lines in the mountainous regions of northern Italy from 1901 until 1976. The first lines were the Burgdorf-Thun line in Switzerland (1899), and the lines of the Ferro... | How long did the AC system last in northern Italy? | {
"text": [
"1901 until 1976"
],
"answer_start": [
210
]
} |
572f52bc04bcaa1900d7684d | Railway_electrification_system | Three-phase AC railway electrification was used in Italy, Switzerland and the United States in the early twentieth century. Italy was the major user, for lines in the mountainous regions of northern Italy from 1901 until 1976. The first lines were the Burgdorf-Thun line in Switzerland (1899), and the lines of the Ferro... | How long did three-phase system operate in Cascade Tunnel? | {
"text": [
"1909 to 1927"
],
"answer_start": [
615
]
} |
572f54f7b2c2fd140056802b | Railway_electrification_system | The first attempts to use standard-frequency single-phase AC were made in Hungary as far back as 1923, by the Hungarian Kálmán Kandó on the line between Budapest-Nyugati and Alag, using 16 kV at 50 Hz. The locomotives carried a four-pole rotating phase converter feeding a single traction motor of the polyphase inductio... | What country has first tried to use single-phase AC? | {
"text": [
"Hungary"
],
"answer_start": [
74
]
} |
572f54f7b2c2fd140056802c | Railway_electrification_system | The first attempts to use standard-frequency single-phase AC were made in Hungary as far back as 1923, by the Hungarian Kálmán Kandó on the line between Budapest-Nyugati and Alag, using 16 kV at 50 Hz. The locomotives carried a four-pole rotating phase converter feeding a single traction motor of the polyphase inductio... | What frequency did the line of Hungarian rail system used in 1923? | {
"text": [
"16 kV at 50 Hz"
],
"answer_start": [
186
]
} |
572f54f7b2c2fd140056802d | Railway_electrification_system | The first attempts to use standard-frequency single-phase AC were made in Hungary as far back as 1923, by the Hungarian Kálmán Kandó on the line between Budapest-Nyugati and Alag, using 16 kV at 50 Hz. The locomotives carried a four-pole rotating phase converter feeding a single traction motor of the polyphase inductio... | What type of the converter was used in hungarian locomotives of that time? | {
"text": [
"four-pole rotating phase converter"
],
"answer_start": [
228
]
} |
572f54f7b2c2fd140056802e | Railway_electrification_system | The first attempts to use standard-frequency single-phase AC were made in Hungary as far back as 1923, by the Hungarian Kálmán Kandó on the line between Budapest-Nyugati and Alag, using 16 kV at 50 Hz. The locomotives carried a four-pole rotating phase converter feeding a single traction motor of the polyphase inductio... | How could the locomotives run on four speed levels? | {
"text": [
"motor could be changed using slip rings"
],
"answer_start": [
382
]
} |
572f54f7b2c2fd140056802f | Railway_electrification_system | The first attempts to use standard-frequency single-phase AC were made in Hungary as far back as 1923, by the Hungarian Kálmán Kandó on the line between Budapest-Nyugati and Alag, using 16 kV at 50 Hz. The locomotives carried a four-pole rotating phase converter feeding a single traction motor of the polyphase inductio... | What system was adopted in Hungary after WWII? | {
"text": [
"Russian"
],
"answer_start": [
680
]
} |
572f575504bcaa1900d76864 | Railway_electrification_system | To prevent the risk of out-of-phase supplies mixing, sections of line fed from different feeder stations must be kept strictly isolated. This is achieved by Neutral Sections (also known as Phase Breaks), usually provided at feeder stations and midway between them although, typically, only half are in use at any time, t... | What invention prevented lines from getting mixed? | {
"text": [
"Phase Breaks"
],
"answer_start": [
189
]
} |
572f575504bcaa1900d76865 | Railway_electrification_system | To prevent the risk of out-of-phase supplies mixing, sections of line fed from different feeder stations must be kept strictly isolated. This is achieved by Neutral Sections (also known as Phase Breaks), usually provided at feeder stations and midway between them although, typically, only half are in use at any time, t... | What was the part of wire in Phase Break sections an arc being drawn from one wire to another? | {
"text": [
"The earthed section"
],
"answer_start": [
684
]
} |
572f575504bcaa1900d76866 | Railway_electrification_system | To prevent the risk of out-of-phase supplies mixing, sections of line fed from different feeder stations must be kept strictly isolated. This is achieved by Neutral Sections (also known as Phase Breaks), usually provided at feeder stations and midway between them although, typically, only half are in use at any time, t... | How were the drivers warned to start coasting the train? | {
"text": [
"warning board"
],
"answer_start": [
1259
]
} |
572f575504bcaa1900d76867 | Railway_electrification_system | To prevent the risk of out-of-phase supplies mixing, sections of line fed from different feeder stations must be kept strictly isolated. This is achieved by Neutral Sections (also known as Phase Breaks), usually provided at feeder stations and midway between them although, typically, only half are in use at any time, t... | What should the driver do in order to open and close the circuit breaker? | {
"text": [
"to shut off power and coast"
],
"answer_start": [
1828
]
} |
572f591404bcaa1900d7688a | Railway_electrification_system | Modern electrification systems take AC energy from a power grid which is delivered to a locomotive and converted to a DC voltage to be used by traction motors. These motors may either be DC motors which directly use the DC or they may be 3-phase AC motors which require further conversion of the DC to 3-phase AC (using ... | What is the main action AC and DC systems have to deal with? | {
"text": [
"converting and transporting"
],
"answer_start": [
388
]
} |
572f591404bcaa1900d7688b | Railway_electrification_system | Modern electrification systems take AC energy from a power grid which is delivered to a locomotive and converted to a DC voltage to be used by traction motors. These motors may either be DC motors which directly use the DC or they may be 3-phase AC motors which require further conversion of the DC to 3-phase AC (using ... | What type of losses happen during conversion and transmission in wires and electronics? | {
"text": [
"ohmic losses"
],
"answer_start": [
736
]
} |
572f591404bcaa1900d7688c | Railway_electrification_system | Modern electrification systems take AC energy from a power grid which is delivered to a locomotive and converted to a DC voltage to be used by traction motors. These motors may either be DC motors which directly use the DC or they may be 3-phase AC motors which require further conversion of the DC to 3-phase AC (using ... | What kind of losses take place in transformers and inductors during conversion/transmission process? | {
"text": [
"magnetic field losses"
],
"answer_start": [
781
]
} |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.