A shark assault boat squadron consists of 8 craft. Each craft has room for 50 soldiers (BFK 140), so each squadron will carry 400 men to its destination. My question is simple: Where are these men coming from? Do these come from barracks inside the ship, or are there some form of barracks attached to the landing bays carrying the assault boats, or do they come from the standard complement of troops each ship carries?

The reason I ask is that I drew up some house rules to specify the amount of troops present in a ship: 5000 per barracks and 2% of the total crew. Which seems to me a reasonable number. Now if you take for instance a mars class battlecruiser with 6 squadrons of assault boats carrying 2400 soldiers in total you run into problems for each choice you make:

From b arracks : Barracks carry more then enough troops to feed the assault boats, but this option would require each ship with assault boats to have barracks.

Landing bay holds troops : If the landing bays hold the troops necessary for the assault, it would give an additional complement of troops aboard the vessel. In the case of the mars battlecruiser example about equal to half a barracks. This would give the ship control over additional ground troops the moment assault boats are placed in the landing bay.

From standard complement : If the troops are drawn from the standard complement of soldiers it would about drain the ship of troops the moment it launched its assault boats. The mars battlecruiser wouldn't even have enough troops aboard (2140 with my house rule) to feed all its assault boats. Draining the ship from all troops would also leave it a sitting duck for any enemy boarding actions.

So does anybody have any thoughts on this? Maybe someone has some house rules of their own?

BFK says around 10% of a crew are typically armsmen. This should solve your problem. Also, the Sharks aren't neccessarily full, and complement of normal Voidmen are likely present aswell (roughly equal numbers to the armsmen in each trip). Compare it the Age of Sail (which RT is based upon) where roughly half (or less) the boarders in a typical Naval Action would be Marines and the rest ordinary sailors (of all ranks), even though the Marines made up a much smaller proportion of the crew (as many crew were busy elsewhere, sailing or fighting the ship). Typically gun crews were used. It could be a means to rapid promotion for those willing to face the risks.

That sounds pretty good actually. So the Mars Battlecruiser would carry about 10,000 or 2 barracks worth of troops. More then enough to fill the assault boats. Could you point me to the page in BFK where it says that 10% of the crew is armsmen?

Page 72, the Those Who Serve sidebar. It gives a rough breakdown of % per 100 men. So in every 100 men 5 to 10 of them would be armsmen (somewhere between 5% and 10% depending on civilian or naval ship, I would guess).

I would agree the boarders would come from the crew, unless there are barracks onboard that could supply other troops.

Whether or not a ships Captain would be bonkers enough to set out equipped with nothing but boarding craft is another matter....