Space between the loading dock and the side of a boxcar?

On straight track, 3/16 inch is enough.  That equates to 9 inches on a prototype dock which is more than enough for the prongs of the brow and the ladders on the car.  John

Depends upon the manufacturer of the boxcar, and the series. I suspect if you measure a few different ones, you'll get your answer, but it won't be a consistent number.

In my designs and testing, I set the docks to 1 foot from the side of the car. On a standard box car (10 feet) That's 1.5" from the track centerline.

What were prototype standards, I wonder?

The space between a loading dock and a freight car?

It's called "no man's land"

Simon

Most steam era freight docks were 3' 9" above the railhead.  The distance from the track centerline varied.

@Ron H posted:

What were prototype standards, I wonder?

Ron,   Hand transportable Dock Plates are roughly 48 x 48 and weigh just under one hundred pounds.  The Safety Legs(those two prongs hanging down) are located about eleven inches from track side - forty-seven from the dock side.  Allowing for maximum slippage when the fork lift truck approaches the dock plate, the greatest distance between the edge of the dock and the edge of the box car can be ten inches.  John

Thanks all !