Sunday, November 19, 2017

Cable problems in SMRT

I saw several postings about the problem faced by SMRT that cables are not labelled properly.

I searched Google and found that there are two types of cables - data cable and power cable.

I suspect that the problem probably lies with the data cable. Let me deal with it first.

I understand that there are equipment that allows two technicians to test the cables. One technican sends a signal down a cable and the other technician see which cable has the signal. The contact each other by mobile phone to coordinate their work.

It can be quite troublesome, if there are a few dozen cables to test, but it should be possible. The data cables in my home are tested by the technicians in this manner.

If there is a problem, it should be possible to identify the cable that is faulty. For example, we expect a signal to be received, but it was not. The signal is required to be sent from one end and to be received by at the other end. This can be traced and rectified. It is hard work but it can be done.

We still have the problem of the low quality of the cables. The longer term solution is to replace all the cables. In the contract to install the new cables, we should specify high quality cables and have a quality control inspection.

We probably do not need to have several hundred cables running all over the place. All the cables at each station should send their signals to a local server who can then communicate with the central system. Using this approach, we can handle tens of thousand of signals without using many cables.

Suppose there are 10,000 devices to be monitored in each station. All these devices send their signals to a server in the station. If any device is not working, i.e. no signal received or the wrong signal is received, the local technician can inspect the problem and fix it.

For example, if a local sensor is not working, it can be identified and fixed locally.

Take the case of the pumps that were not working in the flooded Bishan tunnel.

There must be some local sensor to detect the height of the water in the tunnel. If the water level is too high, an alert can be sent to the local server and the central server.

The central control room can check the monitor of the local station to make sure that the station staff is monitoring the signals.

The data that needs to be shared centrally can be send from the local server to the central server. These data are most likely to concern the trains passing through and also sensors on "foreign objects" that are found on the tracks.

I consider myself to be an expert in data base processing and storage. I understand what is needed to carry out the sensing and to send the data to a database for processing and for alerts to be sent out.

I wonder if SMRT and LTA have people who are able to use the data in a "common sense" way to handle the maintenance and inspection. Based on the problems that have occured recently, I think they do not have the experts who can take charge.

Maybe SMRT or LTA should contact me? I know that the new chairman of SMRT, Seah Moon Meng, is an expert in this area as well. I hope that he can address the issue. But he can also contact me to share ideas.

Tan Kin Lian

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