Yes, I saw the two different ponton bridges. One is a treadway. For the sake of those who don't know, the treadway is the one with the two individual steel tracks across the pontons and would carry heavier loads such as tanks.
Floating bridges were as follows:
The Light Ponton Bridge M1938 was a floating bridge capable of carrying 10-ton traffic in one direction.
The Heavy Ponton Bridge M1940, although similar to the light ponton, was much heavier and carried a 25 ton load.
The Steel Treadway Bridge was designed to carry medium tanks. It had steel treadways for runways, which were emplaced by means of a truck mounted crane. It used special rubber pontons.
Show me bridge pictures anytime and you know I'll be a happy camper. 
Proud Daughter of Walter (Monday) Poniedzialek
540th Engineer Combat Regiment, 2833rd Bn, H&S Co, 4th Platoon
There's "No Bridge Too Far"