LNERGE

I've got TPOs that operate with

HD 3-rail

HD 2-rail

Triang (and Hornby) mechanical ramp

As mentioned above the HD offerings have a socking great solenoid that whacks the "net" and the delivery door open. Only a tinplate coach could survive the forces involved!

The benefit of the HD setup is that it only operates when you want it to, if it passes the apparatus without the button being pressed, the doors stay closed. The Triang and Hornby version opens the doors each time it passes, whether there are mailbags to be collected/dropped or not.

My first post should have had a "tongue in cheek" smiley after "I think its been done before...."

Unless you have some sort of a lineside trigger, you'd have to have "net" boards at a suitable distance before the apparatus to remind you to deploy the pick up net in time....

I can't use an extra rail with dcc so it will have to be something else. Magnets may be worth a try.

Reed switch?