juliensimon/wikidata-submarine-classes

Wikidata Submarine Classes

665 submarine classes from Wikidata (CC0): countries of origin, operators, manufacturers, dates, production numbers and, where recorded, length and draft - a catalogue of classes from midget boats to ballistic-missile submarines.

665 rows x 20 columns, stored as zstd-compressed Parquet.

Usage

from datasets import load_dataset

ds = load_dataset("juliensimon/wikidata-submarine-classes", split="train")
df = ds.to_pandas()

Schema

Column	Type	Description
class_qid	string	Wikidata identifier of the submarine class, e.g. Q330080. Unique per row and the stable key; class names are not unique.
label	string	English label of the class (e.g. Typhoon-class submarine). 53 labels are shared by several classes (one per navy); 4 classes have no English label.
description	string	English Wikidata description, when present.
wikipedia_url	string	English Wikipedia article about the class, when one exists.
countries_of_origin	string	Countries of origin (Wikidata P495), English labels, sorted and joined with '; '.
country_count	int32	Number of countries of origin recorded (0 when none).
operators	string	Operators (Wikidata P137), typically navies, English labels, sorted and joined with '; '.
operator_count	int32	Number of operators recorded (0 when none; up to 11).
manufacturers	string	Manufacturers (Wikidata P176), English labels, sorted and joined with '; '.
manufacturer_count	int32	Number of manufacturers recorded (0 when none).
length_m_min	float64	Smallest recorded length in metres (Wikidata P2043, converted to metres by Wikidata). Equals length_m_max for nearly all classes. (m)
length_m_max	float64	Largest recorded length in metres. (m)
draft_m_min	float64	Smallest recorded draft in metres (Wikidata P2262). (m)
draft_m_max	float64	Largest recorded draft in metres. (m)
total_produced_min	int32	Smallest recorded number of boats built (Wikidata P1092). Zero is meaningful - the class was planned or cancelled.
total_produced_max	int32	Largest recorded number of boats built.
inception_year	int32	Year of inception (P571) when the date is year-precise, else empty; the earliest value when several are recorded.
service_entry_year	int32	Year the class entered service (P729) when year-precise, else empty; earliest value.
service_retirement_year	int32	Year the class left service (P730) when year-precise, else empty; earliest value.
quality_flags	string	Semicolon-separated, alphabetically sorted flags (empty when none): coarse_date_withheld, inception_after_service_entry, unlabelled_countries, unlabelled_manufacturers, unlabelled_operators.

Data quality

Every build is validated before publication; a failing check blocks the upload. Checks applied: schema, dtypes, row_count, nulls, duplicates, row_drop, bounds, critical_columns, column_completeness, unique_key, ordered_pairs. A machine-readable quality_report.json ships with the dataset.

Completeness versus source: The class list is compared with the Wikidata Query Service's own COUNT of submarine classes and must match exactly; class ids must be unique; every property row must refer to a listed class. Query-service errors and timeouts abort the build.

Column	Non-null	Completeness
class_qid	665 / 665	100.0%
label	661 / 665	99.4%
description	576 / 665	86.6%
wikipedia_url	460 / 665	69.2%
countries_of_origin	549 / 665	82.6%
country_count	665 / 665	100.0%
operators	562 / 665	84.5%
operator_count	665 / 665	100.0%
manufacturers	258 / 665	38.8%
manufacturer_count	665 / 665	100.0%
length_m_min	136 / 665	20.5%
length_m_max	136 / 665	20.5%
draft_m_min	105 / 665	15.8%
draft_m_max	105 / 665	15.8%
total_produced_min	112 / 665	16.8%
total_produced_max	112 / 665	16.8%
inception_year	326 / 665	49.0%
service_entry_year	127 / 665	19.1%
service_retirement_year	45 / 665	6.8%
quality_flags	4 / 665	0.6%

Data source

• Wikidata Query Service - instances of submarine class (Q1428357): https://query.wikidata.org/sparql

Known limitations

• Wikidata is crowd-sourced, so coverage depends on volunteers. Of 665 classes, countries (82%) and operators (84%) are well filled but technical specifications are thin - length is recorded for only about 20% of classes, draft 16%, total produced 17%. Treat this as a catalogue of classes, not a specification sheet.
• Displacement, speed, beam and crew are deliberately not published - Wikidata holds displacement (under the generic mass property) for only 13 classes, speed for 32 and beam for 12.
• There is no test depth, armament-by-weapon or sonar information, and the dataset contains no classified or non-public data - everything is what Wikidata contributors recorded from public sources.
• Class names are duplicated and not unique - 53 labels are shared by several classes (for example B-class submarine appears for seven different navies), so use class_qid as the key. Four classes have no English label.
• Multi-valued fields are kept complete - countries, operators and manufacturers are sorted lists with a count, and length, draft and production are published as min and max. 143 classes have several operators (up to 11). Years use the earliest recorded value.
• A year is published only when the Wikidata date has year precision or finer - decade or century dates are withheld and flagged coarse_date_withheld.
• Service entry never follows retirement (a hard rule, zero exceptions among 45 classes that have both). Inception is later than service entry for 2 of 128 classes, which are kept and flagged inception_after_service_entry, within a documented tolerance of 3%.
• Values come from the live Wikidata at query time, so the dataset changes as the community edits; a refresh can add, correct or remove classes, and the build fails if more than 5% of classes disappear.
• Wikipedia article URLs are links only - no Wikipedia text is included.

Update frequency

Refreshed monthly by a scheduled GitHub Actions workflow.

License

CC0-1.0

Citation

Wikidata contributors. Instances of submarine class (Q1428357), retrieved with the Wikidata Query Service. Wikidata structured data is available under CC0 1.0. https://www.wikidata.org/wiki/Q1428357