GOST 21447-75 PDF

Full title and description

GOST 21447-75 — "Контур зацепления автосцепки. Размеры" (English: "Coupler contour line. Dimensions"). The standard specifies the contour (profile) and principal linear dimensions of the engagement surface of the automatic coupler used on broad‑gauge railway rolling stock.

Abstract

This short standard (4 pages) defines the geometric contour and dimensional parameters for automatic coupler engagement interfaces to ensure interchangeability and reliable coupling between railway vehicles. It was prepared for application on broad‑gauge railways and replaces an earlier technical specification (OST NKPS 6453/103).

General information

• Status: Active / in force (listed as действующий in Russian standards databases).
• Publication date: Introduced 1 July 1976 (approved by Gosstandart USSR 30 December 1975; published 1976).
• Publisher: State Committee for Standards of the USSR (Gosstandart); original edition published by the Publishing House of Standards (Издательство стандартов).
• ICS / categories: 45.060 — Railway vehicles.
• Edition / version: GOST 21447-75 (original 1975/1976 designation — the "-75" indicates the year of approval 1975; introduced in 1976).
• Number of pages: 4.

Scope

The standard applies to the contour of the coupling engagement surface of automatic couplers fitted to rolling stock of broad‑gauge railways. It establishes the nominal contour lines and principal dimensions for the mating surfaces that form the mechanical engagement during coupling, so as to ensure dimensional interchangeability and correct mating of coupler parts across vehicles.

Key topics and requirements

• Definition of the coupler engagement (contour) profile and reference drawings.
• Principal linear dimensions and nominal sizes for the engagement contour.
• Permissible dimensional tolerances and references to measuring practices for contour verification.
• Requirements to ensure interchangeability of coupler mating parts between rolling stock.
• Replacement/withdrawal history (replaces OST NKPS 6453/103).

Typical use and users

Used by railway vehicle designers and manufacturers, coupler and component suppliers, maintenance and repair workshops, railway technical regulatory authorities, and laboratories performing dimensional verification of rolling‑stock coupling equipment. Also referenced by engineering departments responsible for fleet interoperability and component procurement.

Related standards

Related documents include prior national specifications it replaced (OST NKPS 6453/103) and other GOST/industry standards covering coupling devices, technical conditions and tests for couplers and rolling‑stock interfaces. Consult national standards collections for adjacent GOSTs in the railway equipment series (see collections under ICS 45.060).

Keywords

autocoupler, coupler contour, engagement profile, dimensions, railway coupler, rolling stock, interchangeability, GOST 21447-75, ICS 45.060

FAQ

Q: What is this standard?

A: GOST 21447-75 is a Soviet/Russian standard that specifies the engagement contour and principal dimensions of the automatic coupler (autocoupler) mating surface used on broad‑gauge railway vehicles.

Q: What does it cover?

A: It covers the nominal contour/profile and key linear dimensions (with tolerances) needed to ensure proper mechanical engagement and interchangeability of automatic couplers fitted to rolling stock. The document is brief (4 pages) and focuses on dimensional geometry rather than full mechanical design or materials.

Q: Who typically uses it?

A: Railway vehicle designers, coupler manufacturers, maintenance and inspection personnel, procurement and standards departments, and regulatory or technical bodies involved in ensuring vehicle compatibility on broad‑gauge networks.

Q: Is it current or superseded?

A: The standard is listed in Russian standards databases as in force (действует). Historical notes indicate it was approved by Gosstandart USSR on 30 December 1975 and introduced 1 July 1976; a previous time‑limitation on its validity was cancelled by Gosstandart decision No. 4328 on 29 September 1981. For absolute confirmation of current legal status and any later amendments or replacements, consult the official national standards registry or a current standards database.

Q: Is it part of a series?

A: It is one item within the body of railway technical standards under ICS 45.060. Related GOSTs and normative documents address other aspects of coupling devices, technical conditions and rolling‑stock interfaces; it also formally replaced OST NKPS 6453/103 at the time of introduction.

Q: What are the key keywords?

A: Autocoupler, coupler contour, engagement profile, dimensions, interchangeability, railway rolling stock, GOST 21447-75, ICS 45.060.