[Beeyar Wunby]

Apologies for the satirical title.

As I'm sure you know, yesterday was stinking hot. We topped the scale at 38C.

The UK railway isn't designed for hot temperatures, and we have to put restrictions in place.

Firstly we had a blanket differential restriction across the whole region of 30/60. Basically that's 60 max for passenger, and 30 max for freight. But on top of that there was an additional local 20 mph restriction for the single line (normally 90 mph !!).

This is both for the rails - the road is already pretty bumpy due to the hot weather drying out the black peat under the ballast, and further direct heat of the sun on the rails could make them buckle and sag so much that derailment is a real possibility.

The other risk is damage to the overhead line, which expands and sags under the heat. There is of course tension compensation built in, but it can only do so much.

I've added a photo of my technique for ensuring I don't overspeed. Because it's so instinctive and automatic to open and close the power handle at given locations, it very easy to forget about the restrictions.This involves sticking insulating tape on the speedo. You can see that I've marked 60 and 20 on the dial. Obviously I pull the 20 one off once I'm off the single line.

Cheers, BW