We had a similar idea. HBG sells these markers for rails and rail stations.
The rail stations are like any other facility = cost 15 IPCs, have built in AA defense. 3 damage points render the rail station un-operational. Maximum damage of 6 points. Any units wanting to travel by rail must start in a territory with a rail station. Rail stations must be placed in territories with an IC.
Rail markers are cheap (3 IPCs) and can be placed in any territory as long as it is adjacent to a territory with another rail marker or a rail station. Units boarding at a rail station can travel along the rails as far as you have rail markers. For example, if there is a rail station in Germany and they have rail markers in Poland, E Poland, Belarus and Smolensk, German units in Germany could travel all the way to Smolensk. If there was NO rail marker in Smolensk, then the German units would have to stop in Belarus then move to Smolensk next turn. All rail movement is Non-Combat Movement, of course.
Like with other facilities or landing planes, you can NOT place a rail marker in a territory that you just captured this round.
Rail markers can be bombed by strategic or tactical bombers. 1 point of damage renders a rail marker un-operational, maximum of 3 damage markers allowed. Rail markers do NOT have built in defense. However, if you have an Anti Aircraft Gun in that territory, it can be used to defend the rail marker. Also, if you have fighters in that territory, they can be used as interceptors.
All of the above seemed like a pretty good rule. We got snagged on the rail limits. After all, you can’t have an entire army traveling across half the continent. At first, we thought about limiting the amount of units to the IPC value of the territory with the rail station. But then that would allow Eastern US to send 20 infantry across the country, or even to Alaska if UK puts rail markers in Canada.
One idea would be to keep it to any 3 land units, which would keep in the same idea as airbases that can scramble 3 planes. We could also tie it to the damage points – 0 damage = 3 units can travel, 1 damage = 2 units can travel, 2 damage = 1 unit can travel, 3+ damage = 0 units can travel. Do you think allowing just 3 units to travel from a totally operational rail station is enough? Would it be worth the investment of possibly buying a rail station? Or even using an existing rail station but having to purchase rail markers and repair any bomb damage?
We also thought about making the limit 5 units and still tying them to the damage points: 0 damage = 5 units, 1 damage = 3 units, 2 damage = 1 unit, 3+damage = 0 units.
As for starting setup, we figured the following territories would start with Rail Stations:
Russia, Novgorod (Leningrad), Germany, West Germany, France, N. Italy, E United States, W United States, and possibly India (Calcutta) and Kiangsu (Shanghai). Or would Kwangtung (Hong Kong) be better than Shanghai? Not entirely sure if Rail Stations should be placed in the far east or not.
As for starting setup for rail markers, there wouldn’t be a lot. Perhaps rail links from Moscow to Leningrad, and perhaps some around Germany (Poland, Greater Southern Germany, Slovakia/Hungary and maybe Romania too) Any further rail links would have to be purchased and placed.
Or, do you think there should be NO rail markers at start up, just rail stations?