Go Back   MLU FORUM > GENERAL WW2 TOPICS > The MLU Sappers Mess


Thread Tools Display Modes
Old 09-04-19, 03:43
Tony Smith's Avatar
Tony Smith Tony Smith is offline
No1, Mk 2** (I'm back!)
Join Date: Feb 2003
Location: Lithgow, NSW, Australia
Posts: 5,042
Default Bailey Bridge washed away in flood

On NZ's West Coast heavy rainfall has washed away a 30 year old Bailey Bridge. The bridge crossed the Waiho River, the stream flowing from the Franz Josef Glacier.

Due to Climate Change, or not, the Glacier has retreated a couple of kilometres in the past few years and deposited a huge amount of gravel and boulders in the river bed. Since the early 1980's, the riverbed of the 18Km long river has filled with gravel and risen 6.5m, altering the floodpain and where storm runoff can escape. It is now channelled under the bridge.

On 24th-25th March, a storm brought 1086mm of rain in 48hrs (over 40 inches!), flushing the Franz Josef valley and rolling bouders down the river bed.

With 8.2m of water under the bridge over a 200m width of riverbed, the forces on the bridge were massive. Despite this, the bridge withstood the force of water and boulders, but was ultimately destroyed by the north riverbank being scoured away. Instead of just dropping the 1 span that was supported at that end, the strongly connected design of the Bailey Bridge dragged 4 spans into the river.

In view of that excellent performance, the new replacement will be another Bailey Bridge, to be built by the Army!
You can help Keep Mapleleafup Up! See Here how you can help, and why you should!
Reply With Quote
Old 09-04-19, 09:26
Hanno Spoelstra's Avatar
Hanno Spoelstra Hanno Spoelstra is offline
MLU Administrator
Join Date: Feb 2003
Location: The Netherlands
Posts: 14,093

Impressive, to say the least about the rainfall, and the durability of the bridge.

Reply With Quote
Old 10-04-19, 06:15
maple_leaf_eh maple_leaf_eh is offline
Terry Warner
Join Date: Mar 2004
Location: Shouting at clouds
Posts: 2,980

Reliable virgin British steel!

Building long spans across gravel floodplains is just plain risky. Channels form for 10,000 reasons and flow patterns are unpredictable. The engineers ought to have put in more support piers and more expansion joints. Connecting the entire span (IMHO) is what caused so much of this damage. But, Baileys are cheap and very easy to assemble. They require next to zero maintenance and every year of service after the first is a bonus.
Terry Warner

- 74-????? M151A2
- 70-08876 M38A1
- 53-71233 M100CDN trailer

Beware! The Green Disease walks among us!
Reply With Quote
Old 24-07-19, 11:07
dcrfan dcrfan is offline
Paul Napier
Join Date: May 2010
Location: NZ
Posts: 50

I suspect the lack of additional piers was the increased risk of flood uprooted tree hang ups.
Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Bailey bridge book Mike Kelly The MLU Sappers Mess 26 26-07-15 10:42
bailey bridge website wim sikkelbein The MLU Sappers Mess 9 09-06-15 15:27
Wanted: 1/6th scale model Bailey Bridge parts Pete M For Sale Or Wanted 16 01-10-12 16:48
Bailey Bridge question Robin Craig The MLU Sappers Mess 4 30-09-09 05:46
Bailey Bridge across the Chehalis River sapper740 The MLU Sappers Mess 12 19-04-09 17:43

All times are GMT +2. The time now is 06:42.

Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2023, Jelsoft Enterprises Ltd.
Copyright © Maple Leaf Up, 2003-2016