AIM: Find out what happens if you pull the emergency handle in a London tube train.

APPARATUS: 1 Northern Line tube train with emergency handles, air conditioning and tannoy systems. 2 fellow passengers. 1 driver. 6-8 pints of Sam Smith?s Ayingerbrau lager.

METHOD: Consume lager. Board train. Sit reading book until train reaches Clapham South and stops. Wait for 90 minutes. Make sure air conditioning is loud enough that no tannoy announcements can be heard. When fellow passengers have left train in frustration after 90 minutes have passed pull all available emergency handles.

RESULTS: The Emergency Handle has no immediate dramatic effects other than to make a high pitched beeping noise, like a smoke alarm, which cuts off quickly. Pulling more than one handle causes the beeping to return but it is very quickly cut off again. The driver appeared after three emergency handles were pulled. His face had turned a reddish colour, though this faded after the tannoy inaudibility was pointed out.

CONCLUSION: Even if a train has been stopped for 90 minutes an excuse for pulling emergency handles is desirable. Train drivers like the idea of getting home as much as you do. Using an emergency handle is not particularly satisfying: future experiments might involve alarms that make more noise. The researcher views this particular experiment with a mixture of deflation and mild embarrassment.