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If cost was no problem and IF parts were still available, 8 LGB track contacts (LGB 17100) and 2 LGB switch drives (LGB 12010) with contacts (LGB 12070) can do this. The motive power must have LGB magnets (LGB 17010) or equivalent installed under them. Although switch drives are used, switches themselves are not needed.

The two paths through the LGB crossing, whether 30 or 90 degrees, are separate. Both routes plus approaches must be isolated from the rest of the circuit. Only one rail needed be so insolated so only a single contact will be needed to isolate a rail from the rest.

8 LGB track contacts control the power by flipping the switch drives first one way, then back. The contacts on a switch drive supply the power to one of the isolated crossing routes, the contacts on the other drive supply power to the other route.

The operation is thus:
As 'Train A' approaches the crossing, it crosses a contact that applies power to the crossing route (i.e. it 'drops out the switch drive or relay controlling 'Train B'. (This seems illogical but it's necessary because of bi-directional travel as will be seen later on.) This contact must be placed a 'train length' from the crossing.

At a stopping length for 'Train B' from the crossing, a second contact is placed which will flip the switch drive for track B, de-energizing the approaching tracks and crossing for track B.

After traversing the crossing, 'Train A' passes a third contact that does exactly the same thing as the second contact. Again, necessary because of bi-directional travel. The contacts essentially are wired in parallel.

At a train's length from the crossing, 'Train A' passes a fourth contact that does the same thing that the first contact did; i.e. drops out the switch drive for track B thus energizing the track for 'Train B'. 'Train A' can now enter a reversing loop or enter a reversing section.

The sequence for 'Train B' is the same, except the contacts are controlling the other switch drive and its contacts are controlling the approaches and crossing for 'Train A'.

The voltages for the two 'trains' can be from the same source or from separate power sources.

The voltage supply for the switch drives can be from the same supply or from a separate source.

Latching relays with at least one contact can be used instead of LGB switch drives. Contacts 1 and 4 would control the unlatch coils, and contacts 2 and 3 would pick up the latch relays.

I know a lot of people do not like to stop their locos suddenly. My first LGB Mogul was purchased before 1990 and has been stopped abruptly many, many times. It's still going strong. (Cross my fingers and knock on wood!)

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