how to get reliable remote uncoupling

We use Greenwich couplings. It is important to ensure that coupling height is accurately set. We use a section of track with a 'buffer stop' with a coupling mounted at the correct height.

First of all, we installed permanent magnets at strategic positions. They were usually OK but we needed to be exactly over the magnet to get them to work and that is easier said than done. Then again, the stock uncoupled as often when not required as when we did! County Gate quickly became populated with unnoticed stock which had detached from consists. Apart from a four year old who thought this was really funny, the rest of us had had enough.

The next attempt was using Peco electromagnets. Naively, I thought, they are Peco.....they must work. Stupidly I fitted the lot before finding that they could not pull off the skin of a rice pudding. We now have electromagnets supplied by Wizard Models which we have quickly nicknamed the 'black holes'. Despite their apparent strength, these magnets were still inadequate to operate the Greenwich couplers as they had been built.

Greenwich coupling etch

With the permanent magnets the couplings operated when the lever arm was cut at position '1' and 8 turns of iron wire wrapped around it. Our trains are largely held in fixed consists so it has never been necessary to have every coupling operate. Where needed, we now use 16 turns of iron wire. Care is needed to ensure that the coupling does not foul any part of the vehicle.

With this mod in place, they will uncouple even if you have not quite parked right over them and again all is well with the world. We have used independent 12V DC power supplies with these as it would be folly to introduce the power drop to electronics.

For places where we need to uncouple at exhibitions, (for us the coal train at the harbour) we have found that it is still very difficult to stop the train at exactly the right spot every time. There would then be a shunt back and forth until the correct position was obtained.

Our solution is not for all because it requires the locos to be of the same length. For us, not a problem as our Garratt rules goods trains on the branch line. I decided that a physical stop would be best and employed a Tortoise motor to do just that. Now, one runs the train very slowly up to the Tortoise wire and we uncouple every time.