Onboard LPG tank

This is the first time I have had a vehicle with onboard LPG, so when travelling through the tunnel what is the process as I don't really want to be laying on my back to get underneath the van to physically turn the gas supply off which is located on the driver's side underneath on the chassis.

Is it acceptable to just isolate the cooker head with the onboard taps? The only problem with that is the volume of gas in the pipe will run the rings for about 5 minutes??

As the system has a crash sensor installed is it necessary???

It's in the AS handbook, you only need to turn off the taps at the manifold. You can if you want light the hob to remove the gas already in the pipework. Sometimes officials want to see that it won't light.

last year they asked to see that the internal taps were off. This year on the way out that asked me to demonstrate that the hob wouldn't light - didn't ask me to power up the igniter! On the way back I was just asked if the gas was off - it was.

A few years ago a train attendant rushed to our van accusing us of cooking - we obviously weren't but he found that the 'work van, transit behind us was cooking bacon on a little gas burner behind closed doors.

I understand your concern. We have been through the tunnel on a number of times. Before loading you are usually taken to one side and they will ask to see that the internal taps are closed.That’s it.No scrambling about under the van required.

Their guidelines may have changed since the last time I used the tunnel in 2022, but while they were satisfied if the internal taps were closed, they were not allowed to physically enter the van to check, just observing from the open doorway. And of course, you can't see the taps from there. Failing to light a gas ring satisfied them.