Please note: all credit goes to AaronVista!
This guide complains how to get Transport Tycoon achievement step-by-step.
How to Get Transport Tycoon Achievement
Select the U.K (They start with 800 convoys already) and start the game.
Once you are in, cancel all your ship production and build convoys.
As your first focus choose “Steady as you go” as this stops the abdication crisis (Choose limited re-armament as your second focus).
Now delete your oversea army and research production 1, construction 1 and concentrated industry.
Build full shipyards in Sussex and Greater London Area.
When you are done your second focus, don’t choose another focus and save your PP and select Free Trade and war industrialist.
Now you have to wait until around August 1936 and you should get the achievement.
Now you should have the Transport Tycoon achievement.