Al Kincer just told me about a great manual that I will be picking up in the near future. This is what he said:
There is an engineer manual, TM 5-35, is the basic manual that makes engineers out of farm boys. Really it is a wonderful manual. If you get a chance to pick one up it would go well in your library.
I also just found this great article on the Bailey Bridge. 
Marion J Chard
Proud Daughter of Walter 'Monday' Poniedzialek
540th Combat Engineer - H&S Company
Also attaching a great one-page reference sheet, which refers to Classes. You will often see a picture of a bailey which a caption stating it's a Class 40 or a Class 70. Now you will know what it means.
Been wanting to place this here for a long time, and someone asked about it today, so it I finally got it done. 
Marion J Chard
Proud Daughter of Walter 'Monday' Poniedzialek
540th Combat Engineer - H&S Company
That is interesting information on the Bailey Bridge!
There are two Double Single Bailey bridges on I-270 between Frederick, Maryland and Washington DC. They are about 10 miles or so south of Frederick and are being used temporarily during the adjacent construction work. (These were obviously taken while driving 
)
Brian Meley
Grandson of Sgt. Frank Altman
157th Combat Engineer Battalion, Company C
Yes, there are actually Bailey's dispersed throughout the country. They are a tried and true method. You can see why the Army used these "puppies"; they work!
Marion J Chard
Proud Daughter of Walter 'Monday' Poniedzialek
540th Combat Engineer - H&S Company