CENTRALISED CONTROL CENTRE

[onestrangeday]

Hi PJW:

thanks for your explanation.
For the railway system that I am currently working with, the interlocking is the distributed type as each station has its own interlocking system and control area. In the normal day's train operation, the operation control centre has authority to control the train movements for the whole railway line by using TCS (including ARS system) and we called OCC (operation control centre) MODE, and in the event of major control centre break down, the system will automatically switched to the Local Control (that is each station accordingly), so there would be no impact on the train services overall.
So I think this is another way of providing the function of 'duplicated' control centre, does UK has this type of design for their control centre?





william

Indeed it would be expensive.
However if paying to duplicate all the interlocking and control equiptment then putting it in a separate building does make some sense as there could otherwise be a "common mode failure" such that the very thing that prevents the use of the main equipment would also prevent the use of the standby- e.g. bomb threat, oil refinery fire, industrial action by staff lock-in etc.

Sometimes can be accoplished almost by accident; Delhi Metro initially had a control centre for its initial lines, network then vastly extended and couldn't be accomodated on that site so new CC for nw lines had to be built elsewhere. Then becomes practicable to arrange to give each CC a limited control over the other's area, so there is a means of keeping the trains moving, albeit in not as an ideal environment, in the event of a catastrophic loss of one centre.

LU is moving control of the entire Circle, District, Hammersmith & City and Metropolitan lines from a variety of large and small distributed cabins etc into just one Signalling COntrol Centre. A "lot of eggs in one basket" that could potentially wipe out a substantial percentage of the entire London Underground, potentially for a period of many months. Likelihood hopefully very low, but consequences huge. Therefore risk worth addresssing.

Conversely the Victoria Line is self contained and there is just one train depot within which the control centre is situated. Not considered worth providing a duplicate, since almost any conceivable factor that would deny use of the control centre building would also deny use of the depot. No value of having back up signalling if there are no trains that can be got to any portion of the line.

So yes you are right. Similar re second portion of your question, there is some increase in complexity.
Maintenance cost re routine work is probably pretty low , but you wouldneed t actually use it occasionally so that it would be kept ready in reserve, staff familiar with perhaps operating railway slightly differently and physically getting to a different site. Ongoing costs of heating and airconditioning etc. Control Centre equipment may need to be totally replaced several times during life of whole installation as technology marches on and obselence occurs - adds to coosts but at least there is a good easy way to update the main CC in this manner by the planned use of the backup whilst work undertaken and then renew the backup itself subsequently.

So not likely to be applicable solution for many schemes, but will be for some and may be increasingly a valid solution as this sort of thing is becoming more practicable; it is often the building itself that may be difficult to fund.......

Hi PJW:

I've read through the attached document. I am thinking if I am a TCS engineer, in what condition would it better to design a duplicated Control Centre ?
(obviously, it's going to cost much and it probably would not accepted by the customers)

(The main reason I could think about is for having duplicated control centre is for the goals of achieving high reliability for the control centre, especially if the control centre is in a very complex and busy network and loss of occ control could cost a big profit loss....)

and what are the major issues that could resulted from duplicated Control Centres? (increase of complexity of traffic control system architecture, increase in the cost of future maintenance cost)

Over the last weeks the London Study group has considered the part question
A new control centre is to be used for centralised control of a complex line or network. What features should be included in the design of its systems in order to achieve sufficient availability for its purpose in a cost effective manner?

The attached isn't a model answer; apart from anything else it is longer than could realistically be achieved and would need to be less explanatory and more tersely focussed on the essentials to answer the question, but it should be a good source of the sort of material from which such an answer can be constructed.