Quote:
Originally Posted by Elrond24
Hi thought I'd butt'in I am not an S&T Engineer but can say the railway is bad environment any comms no matter how sophisticated.
My experience lies in Power Transmission, but the basis of signal telecommunication is that on Overhead Power Tranmission DC signaling is used and on DC Transmission AC signaling.
Bad - in that our rectifier,s induce 300 hz into all adjacent copper cable's, our HT cable surges (be it for our network or the REC), induce upward of 1,500v, mother nature via Lightning strikes at or close to running rails destroy most front ends, TOC induce further interference via chopper ccts in their trains, every night especialy in the London area track ccts(running rails) are disturbed due to engineering. I will not go on !!
The greatest disapointment that Network Rail cannot extend their existing Fibre optic system nationwide for commerial use.
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So the signaling data is at 300Hz?
I remember many years ago that ntl actually came to an agreement with Network Rail or whoever it was at the time, to use the railway fibre/comms ducts in the South Wales valley's. As far as I'm aware they never actually made anything of this agreement, dont quote me but I think the agreement involved ntl using the ducts to run or upgrade the existing fibre routes and offer dark fibres for Network Rail to use. I dont remember the exact details, but had the information at the time from someone involved in the discussion.
The deal was struck (if it was ever signed) at a time when ntl in South Wales were called ntl but were in fact CableTel, It was around the period that CableTel bought ntl but before they bought any of the CWC/Comcasts/Diamond mob etc.
If they had never gone out and bought these companies we would probably of still seen the same end result, ie. One cable company. I do believe though we would of seen more areas, especially profitable ones serviced with cable.
I believe that CableTel/ntl buying up most of the opposition early on had a big impact on the overall availability of cable in the UK.