Hi The secret to DC wiring of
Hi
The secret to DC wiring of reversing sections is that the power supply is made at the point where the loco is and that all trailing turnouts have cuts beyond the frogs. A train travels into the reversing loop with the turnout facing, this gives a choice of right or left but either way the train can enter the reversing section without problem. Once into the loop the power should be switched so that it is supplied to the loop so that when the turnout is switched train power stays the same. This does mean that as the train exits the loop and the power can be switched back to outside the direction has been reversed but as it happenned little by little the train never noticed.
This layout is one of those puzzles - "How many reversing sections can you count". I make it 3 + 1 Y but it seems that I should be able to find more in it somehow. The only further ones are caused by the doubling of the track at the top and the very large one starting at the turnout to the left of the siding fan and running diagonally up, round top right, down to bottom right and back through the Y, which is so long that you can reverse a train that's 2/3 the circumference of the outer track. Unfortunately it is only possible to enter this loop from the loop in the top left which can't take a train longer than about 1/4 of the circumference.
There is a method of doing it totally seemlessly and with the train running totally automatically with several trains on the layout simultaneously. This is called SuperBlock. The layout is divided into a number of sections which are connected to the neighbouring sections by communication wires which give the status in the adjoining sections. A train can only enter a section if it is vacant, as the train enters the section checks whether the next section is also vacant and if not the train will start to slow to a crawl finally stopping at a designated point. Obviously the slow and stop points can have appropriate signals. When the section ahead becomes vacant the train will automatically accelerate back to speed.
Each section can have it's own specific speed limit so that when a train enters the section the train accelerates or decelerates to the designated speed.
The system becomes more complicated with two way running, as here, as if two trains are approaching each other with a vacant section between both would see the vacant section until one entered and this might not give enough room for the second to decelerate without entering the section as well. So as two trains are approaching a vacant section the nearest can be allowed to enter but the further must be told to stop in the previous section.
The communication wires follow the same routes as given by the turnouts using additional accessory switches. This means that the trains automatically run in accordance with the turnouts and any additional switches used to stop the trains. As these are probably at points that signals would be used in this is sometimes called signal centric in that the system is effectively controlled by the signal box alone. Obviously additional control can be provided for shunting but this only needs to be a variable potentiometer as the power amplification is handled by the system.
This layout would require about 11 sections, the controller kits cost about £9 each. It's not really a very suitable layout and you'd be hard pushed to run more than two trains simultaneously while normally 9 sections would allow 3-4 and it would be impossible to run a second train while shunting the yard for instance because there's no headshunt, in fact the left hand end is a critical area used by all routes.
Criticising the layout - I think there are too many reverse loops, there should be a headshunt for the sidings so trains can continue to run during shunting and there should be another siding or spur away from the main yard.
Archie