A Norwegian coupling or coupler (also known colloquially as a chopper coupling or claw hammer coupling), is a manually operated
coupling at each end of some
narrow-gauge railway
rolling stock. It consists of a central buffer incorporating a hook that drops into a slot in the opposing central buffer.
The system is only found on
narrow gauge railways with a gauge of or less on which low speeds and train loads allow a simpler system than, for example,
knuckle couplers. Norwegian couplings are not particularly strong, and may be supplemented by auxiliary chains. Not all Norwegian couplings are compatible with one another since they vary in height and width. Some may permit a hook from both rail vehicles to be in place; others may be limited to one.
The Norwegian coupling was developed in
Norway
Norway, officially the Kingdom of Norway, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. The remote Arctic island of Jan Mayen and the archipelago of Svalbard also form part of the Kingdom of ...
about 1870, when the main railway network was built to narrow gauge. During the 20th century, these lines were
rebuilt to or closed. Since the rolling stock needed to be replaced, a change was made to
buffers and chain couplers. Nowadays they can be seen only at museum railways, such as the
Setesdal Line and
Urskog–Høland Line.
The
New Zealand Government Railways also moved to buffers and chain couplers but during the 1970s they developed a large, heavy-duty version of the Norwegian coupler, which was first applied to a fleet of
diesel-electric locomotives from the United States fitted with
knuckle couplers for
North Island Main Trunk express freight trains. However, the knuckle couplers were replaced with heavy-duty Norwegian couplers to increase their availability for other routes. Since then, Norwegian couplers have largely been replaced with knuckle couplers.
In Australia, Norwegian couplers were used on lines:
Queensland Government Railways,
Western Australian Government Railways and the
Midand Railway, and most of the narrow-gauge lines of the
South Australian Railways. Vehicles of the latter now operate at the
Pichi Richi Railway, which has retained the Norwegian couplers.
On railway lines where rolling stock always points the same way, the mechanical hook may be provided only on one end of each wagon. This was the situation on the
Lynton and Barnstaple Railway, a narrow gauge line in
Devon
Devon ( ; historically also known as Devonshire , ) is a ceremonial county in South West England. It is bordered by the Bristol Channel to the north, Somerset and Dorset to the east, the English Channel to the south, and Cornwall to the west ...
, England, and still applies on the
Isle of Man Railway. Similarly, the hand brake handles may also be on one side of the wagons only. The Lynton and Barnstaple Railway originally used side chains in conjunction with Norwegian couplers, but they were eventually found to be unnecessary with the slow speeds prevailing () and were removed within a year or so of the line opening in 1898. The Isle of Man Railway still connects its side chains in operation.
Kenyan railways,
Uganda Railways,
Tanzanian Railways and
Mountain Railways of India use the Norwegian coupler. In Indonesia, ''
Staatsspoorwegen'' (today
Indonesian Railway Company) rolling stock used Norwegian couplings for its rolling stock.
Gallery
File:Shell oil tank car "Uc" 1031 ATLIB 314385.png, Norwegian Couplers
on New Zealand tank wagon
File:Alco WDLR locomotive 1995.jpg, Norwegian Couplers
on ALCo Ex-WDLR FDLR Loco
File:URCengines.jpg, Norwegian Couplers
on Uganda Loco
File:Nilgiri Steam Engine.jpg, Norwegian Couplers
on India Loco
File:Replica Baldwin loco "Lyn".jpg, Replica Baldwin loco "Lyn" with Norwegian couplers
See also
*
Bell-and-hook coupler
*
Draft gear
*
Nilgiri Mountain Railway
*
Railway coupling by country
References
{{DEFAULTSORT:Norwegian Coupling
Couplers