Driving Van Trailer
A Driving Van Trailer is a British purpose-built control car railway vehicle that allows the driver to operate with a locomotive in push-pull formation from the opposite end of a train. A key benefit of operating trains with DVTs is the requirement for fewer locomotives; for example, a second locomotive would otherwise have to join at the other end of the train after arrival at terminal stations to lead the train's onward journey.
The Mark 3 DVT was originally designed and produced by British Rail Engineering Limited during the late 1980s and early 1990s. Unlike many other control cars, such as the Mark 2 DBSO, the DVT visually resembles a locomotive, specifically Class 90 for the 82/1 Mark 3 series and Class 91 for the 82/2 Mark 4 series; thus when the train is operating in push mode, it does not appear to be travelling backwards. The vehicles do not have any passenger accommodation due to health and safety rules in place at the time of construction that prohibited passengers in the leading carriages of trains that run faster than.
The later-built Mark 4 DVT was specifically developed to work with the new Mark 4 carriages of the InterCity 225 on the East Coast Mainline while the Mark 3 DVT was built to work with the Mark 2 and Mark 3 carriages which then comprised the InterCity rolling stock on the West Coast Main Line. A planned Mark 5 DVT was never produced. Following the Privatisation of British Rail, various private sector train operators have opted to use DVTs in their services. In some cases, such as Wrexham & Shropshire's services between London Marylebone and Wrexham General using Mark 3s and Class 67 diesel locomotives, the DVTs required modification to work with new types of locomotives. Other operators have opted to have their DVTs outfitted with diesel generators or even traction apparatus, the latter case resulting in the experimental Class 19 locomotive.
Development
The DVT concept is similar to the Mark 2 DBSO but, unlike its predecessor which was rebuilt from existing stock, it was a new build vehicle manufactured specifically for this purpose. The first design of DVT was designed to match Mark 2 and Mark 3 coaches. The second design has a narrower profile, similar to Mark 4 coaches, which would enable it to be converted to tilting operation if required in the future. The nose of the vehicle was styled to closely resemble the Class 90 and 91 locomotives that they were paired with.The original Mark 3 DVTs, which operated on the West Coast Main Line, used the RCH jumpers to carry the signals, therefore allowing the same cables to be used for lighting and the public address system, as well as driver-guard signalling. The and locomotives had to be retrofitted with RCH cables, replacing the older multiple working jumpers that some of them had been fitted with.
The InterCity 225 sets operate on the East Coast Main Line; the Mark 4 DVTs and locomotives operate in push-pull formation utilising a time-division multiplexer to send control signals along specially screened cables which run the length of the train. The locomotives usually face north, away from London, only being changed occasionally in rare circumstances; this is because the Class 91 depots are situated at the north end of King's Cross and Leeds stations respectively, allowing easy changeover.
When a train is operated by a DVT, the control signals are encoded and multiplexed onto the cables by the TDM equipment in the DVT. At the locomotive, these signals are demultiplexed by the TDM equipment and the signals are used to control the locomotive. The air braking system is operated directly from whichever cab the driver is driving from. If the TDM fails and cannot be reconfigured, the train may still operate; however, if the DVT is leading, it will be necessary to uncouple the locomotive and attach it to the front of the train.
In addition to the driver's cab, some DVTs have luggage and cycle storage space and a guard's office. One DVT was fitted with a traction gel applicator. A number of Mark 3 DVTs have been fitted with generators to provide power to on-train equipment. One has been fitted with traction equipment, becoming the experimental Class 19 locomotive.
Mark 3 DVT
InterCity West Coast
's Derby Litchurch Lane Works built 52 Mark 3 DVTs to operate with Mark 2 and Mark 3 sets in push-pull mode with Class 86, 87 and 90 locomotives on InterCity West Coast Main Line services from London Euston to Wolverhampton, Manchester, Liverpool and Glasgow allowing the retirement of the Class 81, 82, 83, 84 and 85 locomotives. The standard practice was for the DVT to be marshalled at the southern end, adjacent to the first class carriages, to allow easy changeover of locomotives at Willesden depot which is situated at the north end of London Euston station. The first was delivered in March 1989.They also operated between Wolverhampton and Shrewsbury, and between Crewe and Holyhead, hauled by Class 47 diesel locomotives. Due to a lack of push-pull equipment, these trains would always be headed by the Class 47 and the DVT at the back of the train.
As part of the privatisation of British Rail, all 52 DVTs were sold to the newly created rolling stock leasing company Porterbrook in 1994 and were operated by InterCity West Coast franchise holder Virgin Trains West Coast from 1997 until both the Mark 2 and Mark 3 sets were replaced by Class 390 tilting trains between 2003 and 2005. During 2002, Mark 3 DVTs operated beyond the West Coast Main Line on a summer Saturday service from Manchester to Paignton with a Class 47 hauled Mark 3 set that was hired to Virgin CrossCountry.
Following the loss of a Class 390 Pendolino in the Grayrigg derailment, a Mark 3 set with a Driving Van Trailer was leased with a hired from English Welsh & Scottish as required. During 2008, Virgin looked at leasing two sets, however, the company decided to retain the Mark 3 set instead. Nicknamed the Pretendolino, this received re-upholstered seating, power points, wi-fi and a full Virgin external repaint at Wabtec, Doncaster in 2009. Virgin used this set with a Class 90 locomotive, hired from Freightliner, on a Euston to Crewe service on Fridays only until December 2012. From 9 December 2013, it was utilised to operate a London Euston - Birmingham New Street train on Thursdays and Fridays only, until its withdrawal in October 2014.
Greater Anglia
Mark 3 DVTs were introduced along with Mark 3 coach sets and Class 90s to the Greater Anglia franchise by National Express East Anglia, operating on the Great Eastern Main Line from London Liverpool Street to Norwich in 2004. They also were hauled by Class 47s from Norwich to Great Yarmouth on summer Saturday services. It was proposed that kitchens be fitted to the DVTs, but this did not proceed. During 2012, all DVTs were transferred, along with the franchise, to Greater Anglia.In January 2020, the first Class 745s electric multiple units entered service. Accordingly, the locomotive-hauled sets were promptly withdrawn from service, with the last set running on 24 March 2020.
The standard practice was for the DVT to be marshalled at the northern end, adjacent to the standard class carriages, to facilitate easy changeover of locomotives at Norwich Crown Point depot.
Silverlink
Between September 2004 and July 2005, Silverlink operated two DVTs in conjunction with Mark 3 and EWS Class 90s on peak-time London Euston to Northampton services.DB Cargo UK
purchased DVT 82146 to operate as part of its DB Cargo Company Train that was launched in December 2004.Hull Trains
In January 2008, DVT 82115 was hired to Hull Trains to operate services on the East Coast Main Line from London King's Cross to Doncaster, with a set of Cargo-D Mark 3s while it was short of rolling stock.First ScotRail
During 2005, the Edinburgh - North Berwick services were operated by English Welsh & Scottish Class 90s with former Virgin Trains Mark 3 carriages and a Driving Van Trailer.Wrexham & Shropshire
started operating push-pull services with DVTs in October 2008 between London Marylebone and Wrexham General, with Mark 3s and Class 67 diesel locomotives. This followed the start of the service in April 2008, with Class 67s operating in top and tail formation. The DVTs required modification to work with the Class 67, involving adding a notched power controller as is used in the locomotive and a 27 wire jumper cable as used on the locomotives, which is known as the AAR multiple-working system. These were renumbered 82301 to 82305.Following a reduction in service levels from December 2010, a Mark 3 set was hired to Chiltern Railways to operate a Birmingham Moor Street to London Marylebone peak-hour service. The standard practice was for the DVT to be marshalled at the southern end.