I spotted something odd looking on the front of a British diesel locomotive recently – a fold down coupler! SO what’s the deal with them?
Turns out the locomotive in question was a Class 57/3, with Wikipedia explaining the reason for the extra coupler at each end.
During April 2002, Virgin Trains West Coast signed a deal with Porterbrook for the rebuilding of Class 47s into Class 57/3s; these were to provide a fleet of locomotives for rescue duties as well as to drag electric trains along routes that lacked overhead wires to power them directly, with it decided to fit the fleet with Dellner retractable couplings. The first of these locomotives were delivered in June 2002.
The retractable couplers are found above the standard screw couplers.
Photo by mattbuck, via Wikimedia Commons
And folded down when needed to couple up to a Dellner equipped multiple unit train.
221144 connected to 57308
They remained in this role until 2008 when the completion of West Coast Main Line upgrade saw Virgin Trains’ need for the locomotive reduce, with six units returned to Porterbrook and leased to Network Rail in September 2011.
Some units having the Dellner couplings swapped out for Tightlock couplings as used on ex-British Rail multiple units.
Rail Magazine writing in 2013.
Six new weapons have been unleashed in the war against delays on the former Southern Region, with Network Rail launching six Class 57/3s capable of rescuing electric multiple units and hauling them at 100mph (RAIL 725).
The locomotives are leased by NR from rolling stock leasing company Porterbrook, having been made redundant from similar jobs on the West Coast Main Line. NR leased the six (57301/303/305/306/310/312) in 2011, and their level of work has slowly increased.
Recent brake modifications allow drivers to operate both the brakes on the ‘57s’ and those of the failed train. The safety interlocks can also be operated on the EMUs from the ‘57’, which means that the trains can be hauled at normal line speed. In some areas, that is 100mph.
NR does not have its own drivers, and so drivers from other companies are hired to operate the locomotives. They are predominantly from GB Railfreight, although Colas Rail and Direct Rail Services also provide crews.
“All six Class 57s have had their couplers lowered by 115mm,” he explains. “It has to be lower to couple to the EMUs. Four are
fitted with Dellner couplers to work with the Electrostars and Desiros, while two can work with Tightlock couplers. These are the couplings fitted to the EMUs built by British Rail, and to the Class 357s used by c2c.”
It gets more complicated, Stewart explains, because five different kinds of electrical adapters are required (two for the Electrostars, for example). They are carried on the locomotives in the former boiler compartments, which remain from their days as Class 47s.
The electrical adapters are vital because they put various supplies from the ‘57’ into the EMU. “The Class 57s have air brakes, and that will translate into the unit,” explains Stewart.
Previously, if an EMU failed the option would be for another EMU to rescue it. This would block the line, and cause major delays. Rescues were easier with Tightlock-fitted EMUs, but not those with Dellner couplings – the trains would be unbraked and have to run at 5mph.
Now, the ‘57s’ can rescue an EMU and keep all its systems running, as well as clearing a blocked line.
“Before, failed units had to be rescued using whatever train was available, was powerful enough, and which could be coupled to the unit,” says Stewart.
“Route controls would have to source the rescue vehicle, and competent fitters, and get them to the depot to collect the emergency adaptor coupler before the recovery train could go out – all of which took valuable time.”
A rescue involving one of the modified ‘57s’ would involve its driver, the driver of the failed unit, plus competent staff, such as a maintenance operations manager or a train operating company fitter, on either side of the coupling. This can be achieved in 15 minutes – a huge time saving over previous procedures, says NR.
Further reading
A closer look at the class 57/3 fleet during the Virgin Trains era.
And a video by @mmlspotter on TikTok showing the class 57/3 coupling up procedure.
@mmlspotter GBRf 57306 lowering its coupling then coupling up to EMR 360108 at Bletchley working 5B60 Kettering to Northampton 24th May 2024 #bletchley #trainspotting #fypシ #fyp #class57 #57306 #gbrf #class360 #360108 ♬ original sound – MMLspotter🏳️🌈