Heritage Train Engineering

 

Heritage Train Engineering

The objective of the Heritage Train Engineering Project is to provide an exhibit which demonstrates the inner workings of two key systems of a 20th Century tube train:  traction motor control equipment and saloon sliding doors.  These ‘in progress’ projects are being developed to show how the trains worked.  In parallel, signal engineers are developing a project to show how the associated signalling worked.

Courtesy of the scrap recycling company, Booths, a driver’s cab, two motor control equipment cases and two saloon sliding doors were sourced from a scrapped 1967 Tube Stock car from the Victoria Line and brought to the Museum Depot at Acton.  Various panels and covers were removed from the traction equipment cases to give better sight of the working equipment.  Working with a specialist metal conservation company (Context Engineering), the large cases were raised in the air and mounted on steel frames, so that visitors can walk underneath to view their inner workings.  The cases contain Pneumatic Camshaft Mechanisms (PCMs), 600V dc line-breakers, contactors, and the reverser, along with control relays and other smaller control equipment.  This style of control gear was the best available technology for some 60 years and was phased out for new rolling stock at the end of the 20^th century, in favour of heavy electronic equipment; it is identical to that currently in use on the Bakerloo Line 1972 tube stock trains.

The equipment on display can be operated from the controls in the cab to simulate its working under ‘normal’ conditions.  As a result, visitors can experience the ‘clunks, hisses and clicks’ of 20th Century tube train operation and understand what causes them.  The cab is accessible to people in wheelchairs.

The most recent phase of work has been to design and build an illuminated electrical diagram, to show the sequence of operation of the contactors and the camshaft mechanisms better to explain the exhibit to visitors.

The two saloon sliding doors have been mounted in a steel frame that represents the structure of the car.  One door is fully operational; the pneumatic engine which moves it is on display, along with the air valves, pipework and electrical interlock switch, which is used to prove that the door is fully closed.  Visitors can operate the door from the push-button controls available at the front of the display.  The plan is to expand the rig so that both doors on display become operational.

The whole project is funded by the London Transport Museum Friends and has been planned and executed by a team of former London Underground employees, who, it is rumoured, are called the ‘Magnificent Seven’.  Design work has started to enable the traction equipment to be operated directly from an Auto Driver Box (ADB) to demonstrate a simulated run between two typical stations on the Victoria Line, which was the first automatic railway in the world.  It is then planned additionally to demonstrate how the non-safety electronic equipment on board the train (mounted under one of the passenger seats) automatically controlled the train’s progress between stations, responding to track commands and within the speed limits set by the on-board signalling safety equipment.  In this way, the train responded to ‘signal’ checks and speed restrictions, stopping correctly in the next platform.