24 Hour Rapid Response Penstock Recovery: Case Study

A live sewage treatment works in London faced an urgent operational risk when a penstock seized and could not be released with any on-site recovery methods. With flows backing up, the site needed a safe, controlled way to free the penstock quickly.

Bramley Engineering stepped in with a rapid-response design, manufacturing a bespoke recovery solution to free the penstock. We delivered a purpose-made device, including a drilling jig, lifting bar, and two load-spreading gusset plates in a 24-hour turnaround, enabling the penstock to be opened in stages, bringing the situation back under control.

  Project Summary

• Client: Gel Engineering
• Project: Design and manufacture of a bespoke emergency penstock recovery device, including a drilling jig, lifting bar, and split load-spreading bracing gusset plates
• Purpose: Provide a safe method to release a seized penstock when conventional recovery methods fail
• Turnaround: 24 hours from concept to delivery
• Location: Live sewage treatment works

The Challenge

Gel Engineering were supporting work on a penstock that had become stuck in position. The penstock acts like a heavy-duty door, moving up and down to control flow. With the gate seized, flows began to back up and the situation was escalating quickly.

The team exhausted all practical options on site, including attempts using lifting equipment such as a 10 tonne jib crane, but the penstock remained stuck. A safe, effective recovery method was needed urgently.

Engineering Challenges

Releasing the penstock was not simply a case of applying more force. The recovery method had to deal with a significant load and avoid creating further problems.

• High recovery loads: Estimated at approximately 20 tonnes due to pressure behind the penstock.
• Threaded bar limitation: The existing threaded bar was not strong enough to carry the required lifting forces on its own.
• No time for survey or scanning: There was no time for a site visit or 3D scanning, so the solution had to be designed using the information available.
• Speed and material constraints: The design had to suit materials available in-house or from local suppliers the same day.

The Solution

Step 1: The initial concept

A lifting bar was the first logical step, drilled through the existing penstock actuator spindle, as the team could not get sufficient grip required on the spindle itself. After modelling the forces in CAD, it was clear that the additional lifting bar would not be strong enough to withstand the physics of the lifting operation and would likely bend and break, so a more robust solution was required. Additional support gussel plates were designed to reinforce the lifting bar from above.

Step 2: Create a secure fixing point with a drilling jig

To get proper grip and apply load safely, we designed a purpose-made drilling jig to drill accurately through the penstock actuator spindle. This created a secure fixing point for the bespoke recovery device, allowing controlled lifting forces to be applied without slipping.

Step 3: Engineer the supporting gusset plates

We designed bespoke bracing gusset plates that support the bar from above and spread the load safely, applying forces inwards towards the spindle rather than up which would likely cause the bar to deform and break.

The final arrangement provided a working tolerance of 10 tonnes per side, giving 20 tonnes total support across the gusset plates and bar to match the forces required for recovery.

Step 4: Manufacture at speed with materials available

Because speed was critical, the gusset plates were manufactured in two parts to accelerate fabrication. The design was also constrained by what materials were immediately available, so the solution was engineered around stock on hand and same-day supply for maximum speed.

Step 5: LOLER-standard testing before delivery

Before it left our workshop, the equipment was tested to LOLER standard to confirm it was safe and fit for purpose.

Step 6: Controlled recovery on site

Using the bespoke recovery device fitted to the penstock actuator spindle, alongside a jack to lift the penstock, the team were able to release it and open it progressively in stages. This improved control during the operation and reduced risk compared with a single high-force attempt.

The Results

• Penstock successfully released after conventional methods had failed
• Controlled staged opening improved safety and stability during the recovery
• Escalation avoided on a live sewage treatment site, reducing wider operational risk
• 24-hour concept-to-delivery turnaround supported an urgent, time-critical response
• The tool can remain on site as a failsafe recovery option for future incidents

What Gel Engineering said:

“From the earliest stages of the project, Bramley Engineering proved to be an invaluable partner, bringing technical expertise, innovation, and a highly collaborative approach.

Bramley Engineering developed robust, practical, and compliant solutions that addressed both the operational requirements of the installation and the complex site constraints.

Equally impressive was their role in the installation phase, where their team worked efficiently, safely, and collaboratively with all stakeholders to ensure smooth delivery on site.

Bramley Engineering’s end-to-end capability, from scanning and design through to fabrication, installation, and regulatory support, demonstrates their value as a trusted and reliable delivery partner. GEL Engineering would not hesitate to recommend Bramley Engineering and looks forward to continuing our successful working relationship on future projects.”

– Robert Hoban, Contracts Manager

Conclusion

Working closely with Gel Engineering, our team moved quickly and collaboratively from problem definition to a safe, workable design, then straight into manufacture and LOLER-standard testing. By modelling the forces first and engineering around the real limitations on site, we delivered a compact recovery solution within 24 hours that helped stabilise operations and provided a practical failsafe option for the future.

Let’s collaborate on your next lifting solution

If you have a lifting, recovery or access challenge that needs a practical, site-ready solution, we can design and manufacture bespoke equipment quickly, then test and certify it so your team can use it with confidence.

Email: enquiries@bramleyengineering.co.uk

Phone: 01525 375225