From: Utopia Planitia Fleet Yards
Somebody wrote this (that would be me, hehehe):
Merchant Marine (MM) represent cargo ships that carry both resources across the convoy lanes and/or supplies from port to port. The same class of ships is used for both these purposes IRL, as far as I know. Wether they carry oil, coal, grain or ammunition, food rations, spare parts is irrelevant. All cargo to be unloaded in ports, using their facilities.
Transports (TR) represent the purpose built long range large ships or converted civilian ocean liners to carry troops and tanks. They often also have cranes, masts, nets, etc. to transfer the troops and vehicles to landing craft if necessary. They often are also lightly armed with AA or light guns.
Landing ships (LS) represent all the different purpose built craft like the LCT, LVP, Higgins, etc. They enable invasions and beach supply.
Of I am not mistaken, the above will soon be the way it works. I welcome that.
All right, you won.
Chancellor Gorkon to Captain James T. Kirk:
You don't trust me, do you? I don't blame you. If there is to be a brave new world, our generation is going to have the hardest time living in it.