Contemporary Perspective on LMS Railway Signalling Vol 2

Semaphore Swansong

Allen Jackson

• Publisher: Crowood
• Year: 2015
• ISBN:
  9781785000737
• Topic: Tecnología e ingeniería
• Subtopic: Transporte ferroviario

For over 150 years Britain's railways have relied on a system of semaphore signalling, but by 2020, all semaphore signals and lineside signal boxes will be gone. In his previous book, author Allen Jackson covered the GWR lines; here, he continues his journey by providing a pictorial record of the last operational signalling and infrastructure on Britain's railway network, as it applied to the former London, Midland and Scottish Railway (and lines owned jointly with other companies). This second volume covers the routes of the London and North Western Railway, the Caledonian Railway and the Highland Railway. Beautifully illustrated with over 400 contemporary colour photographs and with detailed information from a 2003-2014 survey, this is an essential resource for railway enthusiasts, rail historians, railway modellers and anyone interested in this aspect of Britain's heritage.

CHAPTER 1

Signal Boxes and Infrastructure on Network Rail

The survey was carried out between 2003 and 2015 and represents a wide cross-section of the remaining signal boxes on Network Rail. Inevitably some have closed and been demolished, while others have been preserved and moved away since the survey started. The large numbers of retired or preserved signalling structures have not been considered in this work and are to be held over for a future volume.

Although the book is organized around the pregrouping companies, the passage of time has meant that some pre-grouping structures have been replaced by LMS or BR buildings.

If you are intending visiting any of them it is suggested that you find out what the current status is before you set off.

For reasons of access and position some signal boxes are covered in greater detail than others and some are featured as a ‘focus on’, where the quality of the information or the interest of that location merits that attention.

Some of the signal boxes have been reduced in status over the years, and while they may have controlled block sections or main lines in the past, some no longer do so but are (or were at the time of the survey) on Network Rail’s payroll as working signal boxes.

Details of the numbers of levers are included but not all the levers may be fully functional, as signal boxes have been constantly modified over the years.

Lever colours are:

Red	Home signals
Yellow	Distant signals
Black	Points
Blue	Facing point locks
Blue/brown	Wicket gates at level crossings
Black/yellow chevrons	Detonator placers
White	Not in use
Green	King lever to cancel locking when box switched out

Levers under the block shelf or towards the front window normally are said to be normal, and those pulled over to the rear of the box are said to be reversed.

There are some boxes where the levers are mounted the opposite way round, in other words levers in the normal position point to the rear wall, but the convention remains the same.

Listed Buildings

Many signal boxes are considered to have architectural or historic merit and are Grade II listed by English Heritage or Historic Scotland. This basically means they cannot be changed externally without permission. If the owner allows the building to decay to such an extent that it is unsafe, the building can then be demolished. The number of signal boxes with a listing is due to increase on the news that they are all to be replaced by 2020.

A Grade I listing would require the interiors to remain the same so that is unlikely to happen with Network Rail structures but may happen with the preservation movement – many boxes have had the interiors preserved as fully operational working museums.

In Scotland the classification system is somewhat different and is as follows: Category A for buildings of national or international architectural worth or intrinsic merit; Category B for buildings of regional architectural worth or intrinsic merit; Category C for buildings of local importance, architectural worth or intrinsic merit.

Signal Box Official Abbreviations

Most signal boxes on Network Rail have an official abbreviation of one, two or sometimes three letters. This usually appears on all signal posts relevant to that box. Finding an abbreviation could be tricky – for example there are eight signal boxes with Norton in the title – until you realize that they are not unique. The abbreviation for each box appears after the box title in this book, if it has one.

Ways of Working

Absolute Block – AB

A concept used almost since railways began is the ‘block’ of track where a train is permitted to move from block to block provided no other train is in the block being moved to. This relies on there being up and down tracks. Single lines have their own arrangements. It is usual to consider trains travelling towards London to be heading in the up direction, but there are local variations and this is made clear in the text.

This block system was worked by block instruments that conveyed the track occupancy status and by a bell system that was used to communicate with adjacent signal boxes.

Signal Box A		Signal Box B
Activity	Bell Code	Activity	Bell Code
Call attention	1	Acknowledge	1
Line clear for express?	4	Acknowledge Line is clear for express	4
Train entering block section	2	Acknowledge...