RAILWAY CONSTRUCTION. 327 



of a typical double-line roadside station with two signal-cabins. 

 The NORTH cabin has to work the signals and points in con- 

 nection with the goods-shed, goods-sidings, and market branch, 

 and the SOUTH cabin, those in connection with the coal and 

 cattle sidings ; and each of the cabins to work the signals and 

 points of that portion of the main line adjoining its own cabin. 

 For siding working, each cabin is quite distinct and independent 

 of the other, but for main-line working the lowering of the 

 signals can only be effected by the joint operation or co-acting 

 of both cabins. 



Assuming a train approaching from A to proceed in the 

 direction towards B, then, before the signalman in the NORTH 

 cabin can lower the UP home-signal C, the signalman in the 

 SOUTH cabin must first pull over his lever and release the slot 

 which retains the signal C at danger, and in doing so the levers 

 in his own cabin will stand locked, and prevent the lowering of 

 the signal D, or opening of points E to allow access from the 

 sidings to UP main line. The cross-over road F G will also be 

 locked for main line clear. When the slot has been released 

 from signal C, the signalman in NORTH cabin can lower the UP 

 home signal C, but before he can pull over the lever for this 

 purpose he must first lock the points H, to prevent access from 

 the sidings to the UP main line, and also the points K L of the 

 cross-over road, to keep the main line clear. A similar operation 

 has to be gone through for a train approaching from B to 

 proceed in the direction, towards A, when the signalman in 

 NORTH cabinjnust first withdraw the slot from the DOWN home- 

 signal M before the signalman in the SOUTH cabin can lower 

 that signal. A small automatic disc is placed in the cabin to 

 indicate to the signalman when the slot has been withdrawn by 

 his colleague in the neighbouring cabin, and for facility of 

 working, the two cabins are usually placed in communication 

 with each other by telegraph or telephone. 



At some stations similar to the above, where there is a very 

 frequent train service, with several of the trains running through 

 without stopping, it is the practice to have a second or lower 

 arm to the home signals C and M, as shown 'on the diagram, 

 these lower arms being only pulled off for through or non- 

 stopping trains, as an indication to the engine-driver that the 

 line is clear in the section ahead. 



In addition- to the leading signals shown in the sketches, 



