signal box
A signal box or signal cabin (in Britain and other Commonwealth countries) or interlocking tower (in North America), is a building from which railway signals and switches or points are controlled. Originally all signalling was done by mechanical means; cables or rods, connected at one end to the signals and turnouts and at the other to levers in the signal box, ran alongside the railway. This required signal towers to have complex arrangements of cabling, levers and pulleys. The guts of this system was the lever frame, wherein one finds this complex cabling arrangement and linkage to levers and controls.
Nowadays, some old-style signal cabins can still be found. Some still control mechanical points and signals. More often than not, the frame has now been removed or is out of use. This is due to widespread power signalling. Most modern countries have little, if any, mechanical signalling remaining in the rail system.
The modern control centre has replaced widespread signal cabins. These centres, usually located near main railway stations, control the track network using computer systems. One such system is CTC, Centralised Traffic Control. 'Track circuits', electrically linked sections of track, indicate the occupation of 'blocks' of track. When a train is on a section of the network, it completes the local 'circuit' and the nature of the electrical signals will show whereabouts exactly the train lies.
In the UK typical modern signal boxes are of the Integrated Electronic control centre or IECC, Entrance-Exit panel (NX) or One control route (OCR) type. Variations of these control systems are throughout the world. U.S. control centers supervise up to several thousand miles, the largest being Union Pacific's Harriman Dispatch Center in Omaha, Nebraska, which controls over 30,000 miles of railroad.
External links
 North American railroad interlocking towers and cabins
Everything you need to know about signalboxes
Over 100 photographs of traditional mechanical signalboxes on Britains rail network
|
|
|
|
This section is sponsored by:
Looking for Signal Box?
Find Signal Box and more at Ansearch. Answers that matter most!
www.ansearch.com
Lowest Priced Computers
Get the lowest prices on laptops, desktops and computer accessories
www.Geeks.com
Laptops - Save Money and Time
Complete Laptop at Cheap Price! Compare &Deal Here.
Laptop-s.cn
HP Laptops & Notebooks
Find great deals on HP laptops & notebooks along with accessories for your computer.
www.shopping.hp.com
Buy Computers Cheap
Get Computer,Laptop,Acces. Save and Order Now!
Portable-LaptopComputers.com
Complete Laptop &Accessories
Need laptop &accessories in new tech? Find here at affordable Price.
Computer-Laptop.net
Get a Mac Computer
Find the Mac computer that fits your needs from the Macbook to the iMac
store.apple.com
Laptop & Desktop Computers
Find great deals & low prices brand name laptops and desktop computers.
www.buy.com
|
