Posted to News on 15th Jul 2008, 00:00
It's full steam ahead with isolator switches
On the North Yorkshire Moors Railway, Keith Taylor-Nobbs, a team leader from Moeller Electric's factory in Worksop, noticed something familiar inside the cab of the LNER (London and North Eastern Railway) B1 steam locomotive. On closer inspection, he discovered two Moeller Electric T0 isolator switches on the fireman's side of cab.
To operate on the mainline, the B1 has to be fitted with an Automatic Warning System (AWS) and Train Protection and Warning System (TPWS). AWS gives the train driver an audible tone and visual indication as to whether a signal ahead is green (clear), red (stop) or yellow (caution). If the signal being approached is displaying a restrictive aspect (red, yellow or double yellow), AWS will sound a horn continuously until the driver pushes a button to acknowledge it. However, if the button is not pressed within three seconds, the train's brakes are applied automatically bringing the train to a halt. TPWS is an enhanced version of this which applies the brakes if a train approaches a red signal too quickly or attempts to pass it. In this situation, the driver cannot cancel the braking action.
The systems only need to be operational when the B1 is running on the mainline, and this is where Moeller's isolator switches come in. Two Moeller T0 switches have been fitted in the cab to enable the driver to easily switch the systems on and off For such an application, the compact and robust design of the T0 rotary switches is ideal.
