The Tilt Authorisation and Speed Supervision System, abbreviated as TASS, is an overlay to

train protection system A train protection system is a railway technical installation to ensure safe operation in the event of human error. Development Train stops The earliest systems were train stops, as still used by the New York City Subway, the Toronto rapid ...

s allowing the control of speeds of

tilting train A tilting train is a train that has a mechanism enabling increased speed on regular rail tracks. As a train (or other vehicle) rounds a curve at speed, objects inside the train experience centrifugal force. This can cause packages to slide about ...

s. It is only installed on the

West Coast Main Line The West Coast Main Line (WCML) is one of the most important railway corridors in the United Kingdom, connecting the major cities of London and Glasgow with branches to Birmingham, Manchester, Liverpool and Edinburgh. It is one of the busiest ...

in the United Kingdom. Its trainborne part is fitted to

British Rail Class 221 The British Rail Class 221 ''Super Voyager'' is a class of tilting train, tilting Diesel-electric transmission, diesel-electric multiple unit express passenger trains built in Bruges, Belgium and Wakefield, by Bombardier Transportation in 200 ...

and Class 390s.

History

The history of TASS is connected to the modernisation program of the

conducted by

Railtrack Railtrack was a group of companies that owned the railroad, track, railway signalling, signalling, tunnels, bridges, level crossings and all but a handful of the railway station, stations of the Transport in England#Rail, British railway syste ...

and successor

Network Rail Network Rail Limited is the owner (via its subsidiary Network Rail Infrastructure Limited, which was known as Railtrack plc before 2002) and railway infrastructure manager, infrastructure manager of most of the railway network in Great Britain. ...

in the early 2000s. The modernisation plan included ambitious targets to increase the line speed from to . This would include the use of tilting trains on the existing tracks. The tilting train tender was won by

Alstom Alstom SA () is a French multinational rolling stock manufacturer which operates worldwide in rail transport markets. It is active in the fields of passenger transportation, signaling, and locomotives, producing high-speed, suburban, regional ...

with its

Pendolino Pendolino (from Italian language, Italian "pendulum", and ''-ino,'' a diminutive suffix) is an Italian family of high-speed tilting trains (and non-tilting) used in Italy, Spain, Germany, Poland, Portugal, Slovenia, Finland, the Czech Republic, ...

technology. The first batch of 53 Class 390s trains delivered between 2001 and 2004, did not differ heavily from the other Pendolino systems. They had been provided to areas with very different train protection systems before and there was a requirement to include features of the

European Rail Traffic Management System The European Rail Traffic Management System (ERTMS) is the system of standards for management and interoperation of signalling for railways by the European Union (EU). It is conducted by the European Union Agency for Railways (ERA) and is the o ...

at the time. The system is based on

Eurobalise A Eurobalise is a specific type of a balise installed between the rails of a railway. Eurobalises are part of the European Train Control System (ETCS). The balises are pre-programmed and contain information that is read by train antennas. One of ...

s to transmit an additional set of speed restrictions on top of the

Automatic Warning System Automatic Warning System (AWS) is a railway safety system invented and predominantly used in the United Kingdom. It provides a train driver with an audible indication of whether the next Railway_signal, signal they are approaching is clear or a ...

Train Protection & Warning System The Train Protection & Warning System (TPWS) is a train protection system used throughout the British passenger main-line railway network, and in Victoria, Australia. According to the UK Rail Safety and Standards Board, the purpose of TPWS is t ...

. TASS allows a maximum of extra speed on sections with enough clearance for the tilting trains.

References

Train protection systems {{rail-transport-stub

History

See also

References