Short answer...maybe.
Long winded answer: It depends
If you cross the tracks with your butt planted firmly on the saddle and the bike has no suspension system, the risk of wheel damage is higher...and so is your butt pain
Front suspension is going to lessen the pain a little and full suspension is going to make you ask "What railroad tracks?"
These guys are doing it wrong
You
should, on any bicycle, ride over railroad tracks like you would ride a mountain bike over obstacles:
Notice how the rider is up off the saddle, his feet are parallel to the ground and his legs...specifically his thighs...are supporting his weight and acting like springs. Your legs and arms absorb more road shock than any bicycle suspension possibly can...short of a 9" travel downhiller.
What this position does is allows your bike to move up and down under you while your body follows a relatively flat line. The bike takes less punishment and your legs can handle the bending and flexing.
Riding like the people do in the RAGBRI picture, means walking across the tracks. Riding like the mountain biker does means flying across them at 10, 20, or 30 mph with more control.
This is only partly right. You shift back so that the front wheel doesn't get trapped by the tracks and you lose control of the bicycle. But the front wheel is the strongest wheel on the bike. It can take more punishment than the rear wheel can. It's best to lean backwards as the front wheel goes over the tracks and then move the center of mass forward...a
little...as the rear wheel goes over the track. This takes weight off the front wheel so that the wheel won't get trapped and you'll crash but then takes weight off the rear wheel so that it isn't damaged by the impact. This kind of body movement is second nature to anybody that has mountain biked...even with full suspension...as can be seen in the mountain bike picture above