CONTACT 0447

The system is not looking for rats. The system is looking for the track.

A geometry car runs the line at low speed with lasers pointed at the rails and writes down everything that is out of tolerance — gauge, cant, twist, the small settlings that mean a sleeper is going. It produces a file. Somebody reads the file. Most of it is nothing.

At one chainage on one line, since March 2019, the file has an entry in it that nobody has been able to close.

It is logged as an obstruction. It is 0.4 metres across, it sits between the rails, it is present on roughly one run in three, and it is not there when anybody goes to look.

It has a reference number because everything has a reference number. The reference number is 0447.

The explanations, in order:

Something's there when nothing's looking, and the machine isn't nothing.

One. Water. There is water at that chainage; there is water at most chainages. Withdrawn when 0447 appeared during a dry fortnight in 2021.

Two. A reflective plate on the cess wall throwing the return. Plate was located. Plate was removed. 0447 continued.

Three. A fault in the car. The car was swapped. Withdrawn.

Four. A fault in the software. This one lasted eight months and produced a patch, and the patch is in the changelog, and 0447 is in the file after the patch.

Five. Somebody putting something on the track. This is the explanation that people prefer and it is the one with the least behind it. There is no access at that chainage that does not go past a camera.

Six. Rats. This was offered by a track engineer in a meeting in 2022 and, according to two people who were in the room, was not a joke. The objection is size: 0.4 metres is a great many rats and rats do not hold still for a laser.

The counter-objection, offered by the same engineer, is that 0447 does not hold still either. It is 0.4 metres across on some runs and 0.35 on others and once, in November 2023, it was 0.9.

I went out with the night gang twice. Both times we walked the chainage and both times there was nothing there, which everybody had told me in advance, and which everybody still seemed to find disappointing.

On the second night one of them — I am not going to name him because he was clear about that — said the thing that I have not been able to put down.

He said the file is the only thing that sees it. Not the drivers. Not the cameras. Not us, walking it with lamps. Just the car, at low speed, with lasers, three times out of ten.

“Something's there when nothing's looking,” he said, “and the machine isn't nothing.”

Then he said it was probably water.