Grain orientation for machine moving scooter board

[Bill Dufour]

I am making a couple of machine moving boards with four casters. Roughly 12"x24" out of 2x lumber.. Obviously the boards will run the long way. I split one down the middle along the grain when I blocked up my lathe wrong. The grain failed not the glue joint right next to the split.
Which way should the grain lay when it is glued up? reading says vertical grain is strongest but flat grain seems less likely to split.
plan is to set machines on these bases to move them around for just a few feet each. the lathe broke through plywood over gravel in the alley moving it to go into a trailer. So i am switching to bigger wheels. That will be the heavest machine by 500 pounds nothing else is over 1,200 pounds.
Bill D

[Edward Weber]

With respect, it sounds like you're trying to re-invent the movers dolly
https://clayton-supply.com/moving-storage-supplies/dollies-casters/
Caster bolts go through both pieces of wood, usually hard maple

[Richard Coers]

If you laminate 2 layers of 3/4" plywood, then grain direction is of no concern. I always lay down 7/16" OSB if I'm moving machinery on a surface other than concrete.

[Bill Dufour]

Yes a movers dolly but with better wheels and no hole in the middle. I figure it could be 1750 pounds on the dolly if the other end lifts up. so it needs a little more beef. The tailstock end plinth is about 10x20 so it would fall through those commercial dollies unless I add a solid deck anyway.
Bill D

[Richard Coers]

Moving that kind of weight over gravel by hand is going to be a huge task. I call the local wrecker company and they charge between $75-$100 to bring out a roll back flat bed. I move the machinery on black pipe to get it to the door.

[Rick Potter]

How about 1 1/8" plywood used in flooring?

[Tom Bender]

A couple of things may help

Thicker boards of course but you won't want the extra height. Can you add something to the underside between the wheels? 2 x 4 or plywood

Apply the load to the edges of your boards, maybe by gluing 2 pieces of 1/4 x 2 x24 plywood to the top.

[Michael Schuch]

A picture of what you have currently would go a very long way in helping you design a strong structure.