When the Housatonic Railroad eventually gets to the point we start operations, it will be done under Timetable and Train Order (TT&TO) rules. I believe this is one of the most fun and challenging ways to operate, and my layout has been designed from the start to work under this system. But I wanted to include a few special twists in addition to what one normally sees on this type of layout, something relatively obscure and seldom if ever modeled, but an important element of running trains under TT&TO -- the use of fusees (pronounced few-see).
Under TT&TO, trains running in the same direction are supposed to maintain a 10-minite separation between themselves. This is normally accounted for in the timetable, but sometimes your train is running behind schedule or not at full speed, and there's a danger of your train being overtaken by another train behind you. Or worse, you are an extra train and no one out there knows about you (it's the extra's responsibility to stay out of the way of the scheduled trains). When that happens, the conductor in the caboose is supposed to light a fusee -- basically similar to a road flare, but it burns for 10 minutes -- and toss it down onto the tracks at 10 minute intervals until the slow or late train can get into the clear.
But that's only half the story -- The rest is what the other trains are supposed to do when encountering a lighted fusee on the tracks. Say that there is in fact a fast train coming up on the slower train ahead of it. The engineer in the fast train comes around a curve and sees a lit fusee on the tracks. The rules state that the engineer must immediately stop the train, because there is an obstruction on the tracks ahead. It's not known how far ahead, or if it is still there -- so the safest course must be taken.
If the engineer can stop the train before passing the lit fusee, he must wait until the fusee has completely burnt out, if he passes it he must wait a full 10 minutes from the time he passed the fusee to ensure that the full interval is observed. Once the interval is satisfied, the engineer may proceed at restricted speed (defined as slow enough to stop the train within half the distance of an obstruction) until either another fusee is encountered, or a place where a train could clear (pass) is arrived at, or the obstruction (A train that has stopped) is located.
In the event a train must stop on the main track flagmen must be sent out before and after the train (rule 99) to protect it.
The use of fusees is an important part of the operating process under TT&TO, but it's almost never modeled because it would be very complicated to implement. But I really wanted to find a way to make that work on my layout. The best solution appeared to be an electronic one. I planned to put an LED embedded in the track in the ballast to simulate a fusee on the tracks, and to trigger it from a pushbutton switch mounted on the fascia. As I will be operating under a fast clock (only 2:1 or 3:1 speed) I needed it to be adjustable so the burn interval would be approximately 10 minutes based on the selected clock speed.
Unfortunately I did not have the electronics knowledge to design and build a circuit that would do this. I searched about on several internet model railroad forums for someone who might be willing to help me with the project, and I was very lucky to meet John M. Smith on one of them. John is an electronics whiz, and thought it was an interesting idea. He agreed to take my requirements and see if he could come up with something.
Well, long story made short, over several months John and I talked and refined the requirements, and made changes based on hardware avaialble and even added functionality. We determined we'd need many fusees on a larger layout like mine, so we could use a larger processor and add as many as five separate circuits on a single board, reducing the cost per circuit.
John suggested we could add another function to each circuit. By using a two-mode toggle switch instead of a pushbutton, we could have the LED lit manually by flipping the switch up -- giving us the effect of a flagman that can be 'recalled' (turned off) at will, while flipping the switch down (momentary contact) would allow us to set the fusee as originally intended. John constructed and sent me two prototype units, and eventually designed and etched his own circuit boards and built up several complete circuits for me.
I got the finished circuits back in May of 2005, and in the last month or so (September 2005) we have begun to install them around the layout. Fed by a 12 volt regulated power supply, several of the circuits are now located around the layout and switches (with plates I designed and cast) have been installed, and the LEDs embedded in the tracks.
2006 - Sometime later, after we started putting up a lot of signage around the layout, I determined that the cast fusee panels just weren't looking as good as I had hoped, compared to the newer, brighter signs. They were getting lost among the other attention-grabbing devices. So I decided to replace them with similar panels to the newer signs. I'm pretty happy with them, and they are much more noticeable.
But the real test is what will the crews think of them? Much to my relief, my construction crew thinks the circuit is the bees knees. They grin like idiots every time someone flips one on, and they constantly flip them on as the pass them walking by in the aisle. I think the novelty is great, and what I'm hoping for is that the enjoyment of using the fusees will help the operators learn more about the rules the railroad will operate under, and that will help everyone out.