IMH News


Powering the Boston Barrier

Hear how we have applied our extensive technical experience when working alongside BAM Nuttall and Mott MacDonald to deliver the hydraulic solution to power the Boston Barrier.

Having successfully engineered the hydraulics on a number of previous flood defence projects such as Palmers Dam in Totnes, the Ipswich Locke System and the Black Sluice Gate in Boston, we were engaged by BAM Nuttall for the Boston Barrier flood defence project.

The engineered solution presented by BAM Nuttall and Mott MacDonald entailed halving the size of the river and implementing a single horizontal sector gate. The gate itself will be made from carbon steel and weigh around 330 tonnes, increasing to 730 tonnes when full of water.

This gave us a number of challenges to consider, as the solution required the barrier to be raised from flat and into position within a short 20-minute timeframe, all the while considering the forces of water and ensuring that the system could operate within huge differences in the design temperature range, between -20°C and 50°C.

In response to these challenges, we developed an engineered solution that would involve the design and manufacture of three hydraulic power units (1 x Main HPU & 2 x Emergency HPU’s), the MHPU having 5-off electric motors and driving 11-off hydraulic pumps​, the EHPU’s having a single pump driven by a diesel engine.

The main hydraulic pump flow was designed to offer up to 202 litres per minute per operating cylinder​. In total there are two cylinders, each weighing in excess of 57 tonnes, that have been designed and manufactured by Hunger.

The project also required a large amount of pipework, more that 800m of stainless-steel, which has been fabricated by us at our workshop. We used a 3D model of the fabrication work to confirm how much steel pipe would be needed for the project, ensuring there was no overspend on materials and giving us the ability to demonstrate how the proposed fabrication solution would save both time and money.

The installed pipework, welded by our experienced team, ranged in sizes from 25mm to 88.9mm diameter and was manufactured in 316L stainless steel. Knowing the extreme environmental variations, the pipework would be subjected too, we ensured the pipework was all high-pressure tested to 445 Bar, enabling it to withstand the pressures resulting from lifting the barrier into its required position in a short space of time.

The project recently reached a great milestone in that it was deployed at the bottom of the River Witham bed and during the testing phase, it was moved into its fully open position.

James Griffiths, Managing Director at IMH commented on the project: “This has been a fantastic large-scale project for the IMH team to work on. It has demonstrated our highly specialised hydraulic expertise and ability to help our customers overcome challenges and successfully meet objectives, employing our deep technical knowledge and our team’s innovative thinking.

“We have an established track record of supporting the delivery of complex infrastructure projects including flood defences, lock gates, moving bridges and tunnelling schemes, and relished the opportunity to work on the Boston Barrier.

“As well as offering engineering expertise, we can supply specialist equipment for infrastructure projects including lock control systems, motion control systems and hydraulic actuators.”

We have over 35 years of hydraulic engineering expertise working on complex projects across the globe which we apply to each and every project, ensuring customer experience reduced lead times, cost savings and robust solutions to our challenges.

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