Each tank has an outlet at the bottom towards the front for a balance pipe to join them together. Have a think about how you are going to be able to join these two flexibly when the tanks are fitted. i suggest inventing a Y joint and flexible rubber pipe with the base of the Y going to the rear buffer for a) draining tanks after use, and b) pumping water into the tanks from an extension tank on your driver trolley.
Next there is an outlet to a simple cock that feeds the injector with warm water so it may not work anyway. Better to have a feed from the trolley again.
Then there is a feed to the axle pump.
There is also an exit needed for the hand pump water pipe and finally an entry for the bypass water to get back into the tank taken to a point just under one of the filler caps so excess water can be seen coming out for you and the boiler inspector to see the axle pump works.
I'm not usre what's on the drawings and if it is one of LBSC's occasions when he left it to the builder then every one is likely to be a bit different. I'll check out mine when I get home. My hand pump is in the RHS tank.
Edited By Diane Carney on 03/11/2014 16:41:00