Normal non opening train bridge, for longer stretches of water, and also increase the speed. I get it's a invisible locomotive carrying cargo wagons but atleast reduce the weight. I get that in real life a cargo boat wouldnt be light but it is ridiculously slow at acceleration and speed, even with nuclear fuel

there is already a bridge mod, "beautiful railway bridges", maybe check it out? it kinda makes the whole "ship business" obsolete though, since you can just build trains everywhere.

there is a mod option to double the ships speed, have you tried that?

Oh forgot about the mods options page, and I'm already using beutiful bridge railways I just want a "official" rail bridge that fits the asthetic of the lifting bridge