The Bailey Bridge panel bridge system has been around since WWII. It has been credited as being one of the top 3 technological advancements that allowed the allies to win the war. After the war, the surplus of Bailey Bridge parts were sold off and distributed around the world. While these bridges were intended to be for temporary use (military temporary use and civilian temporary use are two different things), some of these old bridges can still be found in use today.
A quick search on google will return all sorts of beautiful modern bridges that are not Bailey Bridges. To me, a Bailey Bridge is a very specific type of panel bridge from WWII or post war sold by Bailey-Uniflote. However listening to colleagues, and even looking at the google search results, it appears that Bailey Bridge is just another word for Panel Bridge. Similar to Xerox and Photocopy, or Kleenex and tissues. So this has muddy some of my search efforts thus far.
The problem I face is trying to determine which of the 4 (maybe more) types of panel bridge systems I may be looking at as they can be very similar in component layout at a quick glance and even some basic measurements.
So far my research has told me that some of the distinguishing factors for these panel type bridges are:
- Panel size
- Panel diagonal members (I, C, HSS/TUBE)
- Deck width
- Transom location
- Transom size
The original Bailey Bridge had a panel length of 10'0" (3.048 mm) from centres of connecting pin holes and a height of 4'9" (1.448 mm) from centres of connecting pin holes. The overall height was 5'1". Anything outside of these dimension would indicate a newer panel system such as an Acrow 700xs or Mabey Compact 200 or the like.
In the Bailey Bridge panel there are two diamond shapes. The diagonals of these shapes were originally I sections. At some later time these sections changed to C-Channels and rumour has it HSS or tube sections were used by certain manufactures. Anyone have any confirmation on how to identify or rule out potential bridge type based diagonal section type? Maybe even some date ranges for the various section type?
- The original Bailey Bridge has a roadway width of _____ and a clear width between trusses of ____.
- The standard widened Bailey Bridge has a roadway width of 10'9" (3.28 m) and a clear width between trusses of 14'3" (4.34 m).
- The Extra Wide Bailey Bridge has a roadway width of 13'9" (4.19 m) and a clear width between trusses of 15'8" (4.77m).
I am not sure what the standard deck width is on an Acrow 300 or a Mabey 100.
On a Bailey Bridge, the transoms are located adjacent to the panel's end vertical and middle vertical. This can been seen in the following diagram and photo:
If the transoms need to be double up to carry a heavier load then there are 4 transoms per bay. Two either side of the middle vertical and 1 inside of each end vertical as shown in the following photo:
For an Acrow 300 style panel bridge, the transom is located at the base of panel's diamond as seen in the following photo:
Mabey 100 transoms are located ?????
- A standard Bailey Bridge has a transom length of 18'0" (5.49 m) with a constant 10" depth. There will be 3 holes near the bottom flange to allow for 3 panel lines.
- A Standard Widened Bailey Bridge has a transom length of 19'11" (6.1 m) with a 12 in depth between under the deck and a 10" depth at the panel lines. There will be 4 holes near the bottom flange to allow for 4 panel lines.
- An Extra Wide Bailey Bridge has a transom length of 19'11" (6.1 m) with a 12 in depth between under the deck and a 10" depth at the panel lines. There will be 3 holes near the bottom flange to allow for 3 panel lines.
- It also appears that transom with a tapered flange also exist while maintaining a uniform section depth
- There is also the M2 and M3 Transoms identified in the US Bailey Bridge Field Manual
Acrow 300 and Mabey 100 transoms are?????
What are the key factors that distinguish Bailey Bridges?
So far I can only tell Acrow 300 by its transom position.
Just found this really nice write up on the Bailey Bridge but it still does not completely answer my questions.