The bridge design that helped win World War II

It’s a simple innovation that helped win a war.

The Bailey bridge was Donald Bailey’s innovative solution to a number of wartime obstacles. The allies needed a way to cross bodies of water quickly, but bombed-out bridges — or an absence of crossings entirely — made that incredibly difficult. That was only compounded by new, heavy tanks that needed incredibly strong support.

Bailey’s innovation — a modular, moveable panel bridge — solved those problems and gave the allies a huge advantage. The 570-pound steel panel could be lifted by just six men, and the supplies could fit inside small service trucks. Using those manageable materials, soldiers could build crossings sufficient for heavy tanks and other vehicles.

As impressive, the Bailey bridge could be rolled across a gap from one side to the other, making it possible to build covertly or with little access to the other side. Together, all the Bailey bridge’s advantages changed bridge construction and may have helped win the war.

Further reading:

John A. Thierry’s contemporaneous history of the Bailey Bridge provides a great overview:

This Army Manual is a great look at how the Bailey Bridge worked:

A number of good papers about the Bailey Bridge are also available, though they sit behind a paywall. You can read Bailey’s account of his bridge:

Denys Begbie and Gwilym Roberts’ paper is a great summary of the Bailey Bridge’s achievements.

The same goes for CJH Joiner’s history:

[daffaargada]

Ah yes, another piece of information that i can randomly mention in a conversation

[zodiark]

Concorde: "the snoop drooped"
Bailey Bridge: "the snoop droppedn't"

[kaustavsen]

The concept is so amazing that even now, in case of an urgent need, the civilian govt, when it calls in the army to help build bridges, they make these, overnight! This is in India that I am talking about. And in some of the more inhospitable terrains, instead of having concrete bridges, these Bailey bridges serve as the mainstay!

[GalluZ]

I'm surprised he acknowledged his meme: the snoot droop. Man what a callback.

[firdausrosli]

In Malaysia, this kind of Bailey Bridge will be built when a existing bridge is no longer fit for usage, while waiting for the government to approve funds to rebuild the original bridge.

[marcusrobertsson]

This brings back memories! When I did my military service here in Sweden 1997-98 I did it as an engineer. Our company was a specialist bridge building company. We soldiers really appreciated this design as it was easy and fast to build. And even though we had some modern equipment at our disposal (like Volvo tractors) we usually used only hand power. Pushing out one of these bridges by hand over whatever obstacle we were facing was a mighty feeling. In Sweden the bridge is known as "balk-bro 2" ("girder bridge 2") which was a constructed name to fit the stamped parts that said "B B m.2".

Fatta!
Säkra!
Lyft!

Those were the commands when lifting one of the bridge panels. 3 people on each side holding onto the wooden lifting bars going through the panel. You really had to think about where you placed the people and match up their lengths so that the load was distributed evenly. And don't have your foot under the panel when you set it down, as one of my comrades did...

[DyslexicMitochondria]

I absolutely hate broken bridges

I just can't get over them

[pavarottiaardvark]

There's an old Bailey Bridge near where I live in Wales. It's a bit rusty and they don't vehicles cross it, but it's STILL STANDING TO THIS DAY.

[patrickd]

As a former Army Engineer Officer, thank you for telling this story so well! We still use them today and it’s a testament to how incredible the design is. These bridges are more durable than you would believe. Only thing to add to this great video is how easy it is to train Soldiers on how to deploy the BB- essentially you can train non-engineers (like Infantry or Armor Troops) in a few hours and they can help rapidly deploy one, even in a combat zone. Bravo Vox 👏

[Avantime]

Here's another interesting trivia: The US later reverse-engineered the Soviet PMP floating pontoon bridge (now one of the most popular of quick-assembly bridges) after seeing the Egyptians using it in the Yom Kippur war.

[johnhowitt]

i actually used to go over a Bailey bridge. In 1947 the Shardlow bridge in Derbyshire was washed away and replaced by a Bailey bridge. we had relatives in Derby and used to cross the bridge on the way to visit them. the traffic flow was limited and so was the speed . i used to both love traveling over the bridge and was scared it would collapse. it was replaced in 1957 when i was 10 and i was most disgruntled.

[superstormthunder]

Ahh yes the winner and losers of WW2
Loser: Hitler
Winner: A bridge

[rocksterking]

HE SAID IT. HE SAID THE THING! 4:10
"The snoot didn't droop."

[ryanleethomas]

Army Engineer Officer here, the Bailey Bridge is still used today, and we spend weeks learning bridging and train on assembling the very same process to cross gaps. It’s cool to see this historical explainer, but it’s especially cool to have built this and know it’s still effective.

[Jakef_]

I had the privilege of putting one of these together in 2009 at Fort Leonard wood Missouri during training, was an awesome experience.

[xirensixseo]

information like this is underrated. the development of the jerry can is another such topic, its so interesting

[zianliva]

When multiple attempts of Poly Bridge finally works

[Mohammed]

0:49 this is Cologne Germany with it's Hohenzollern Bridge

[bulwinkle]

My Dad was in the Royal Engineers during WW2. His unit built many of these bridges including a Bailey pontoon bridge over the Rhine.

[gavalanche]

I wish you'd talk about the modularity more. These bridge pieces could be used to span a small ditch or gully, or be stacked and layered to make incredibly huge spans. They're like full size Meccano.