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Aluminium waler frame braced against trench sheets, with edge protection above

Aluminium Waler Frame Systems

A light alloy waler frame for bracing trench sheets around live services

  • Rails from 1.5m to 5m
  • Light enough to handle by hand
  • Hydraulics run on water, not oil
  • Fast lead times
  • Competitive rates

An aluminium waler frame (also called a waling beam or horizontal waler system) braces trench sheets around an excavation from the inside, holding back the ground while your team works. Because the sheets are placed individually around the frame, gaps can be left exactly where pipes or cables cross the trench, which makes walers the system of choice where a trench box can't be used because services are present.

The frame is built from light alloy waler rails, from 1.5m up to 5m long, braced apart by hydraulic struts. A rail weighs between 16.5kg and 55kg and the hydraulic ram 11kg, so the parts can be carried and assembled by hand, in the excavation if needed. The pump runs on water, with no hydraulic oil to spill into the ground. Shorter rails are popular with utility companies, and the system is often chosen for city centre excavations where disruption has to be kept to a minimum.

Applications

  • Shoring trenches where gas, water or telecoms services cross
  • Utility connections and repairs
  • City centre and highway excavations
  • Manhole and chamber construction
  • Deeper trenches, with frames installed at multiple levels

End bearers

End bearer rails can be used to close the short ends of the frame, so the trench sheets are supported on all four sides of the excavation rather than just the two long faces. We stock three sizes, adjustable in 75mm increments and fixed with pins and R-clips:

Installing a waler frame

The usual method is dig and push. The frame is assembled on the surface, pumped out to size and lowered into a shallow pit, then sheets are pushed around its perimeter using the rails as a guide. Excavation and sheet-driving then alternate, with temporary frames restraining the sheets, until the formation level is reached. For deeper excavations, frames are installed at two or more levels. The full sequence, including the pre-driving alternative, is in the user guide.

Safety points our engineers insist on:

  • Never enter the excavation before adequate shoring is in place
  • Work to a lift plan; the heaviest frame is 168kg, and hanging chains must not be used for lifting
  • Inspect every component and the hydraulics before use, and reject anything damaged
  • Install edge protection, safe access and a davit system where required
  • Leave at least 100mm of extension on the rams so the frame can be retracted for removal

Get In Touch

For hire rates or advice on any of our waler frame systems, please contact your nearest depot.

FAQs

What is a waler in construction?
A waler (also spelt whaler, and called a waling beam) is a horizontal beam that spreads load along a line of trench sheets or piles. In an excavation support system, a pair of walers braced apart by struts forms a waler frame, which holds the sheets against the ground pressure on each side of the trench.
When should I use a waler frame instead of a trench box?
Use a waler frame when services cross the excavation. A trench box is a solid-sided unit, so a live gas main or telecoms duct running through the dig rules it out. With a waler frame the trench sheets are placed individually, leaving a gap where each service passes, and the frame braces the sheets from inside. Walers also suit confined city centre sites where a box would be too heavy or too disruptive to install.
Are aluminium walers as strong as steel walers?
For the trenches they are designed for, yes. Our aluminium waler rails carry up to 80 kN/m on shorter frames, with a permissible moment of 18 kNm, and the light alloy is what makes hand assembly around live services possible. Steel walers come into their own on wider, deeper excavations carrying higher loads; for those we hire hydraulic bracing systems instead, and our engineers can advise which your job needs.
How deep can a waler frame excavation go?
There is no single figure, because it depends on the ground, the sheets and the loads around the dig. The frame level (or levels) and the safe depth are set by the temporary works design; deeper trenches use two or more frames, installed as the excavation progresses. Our in-house engineers provide temporary works design for waler schemes.
What is a battered edge?
Battering means cutting the sides of an excavation back at a safe angle instead of leaving them vertical, so the ground above the supported zone cannot collapse into the trench. During waler installation, the top of the dig can be battered or stepped before the first frame takes over support below. Whether it is needed depends on your ground conditions and should be addressed in the risk assessment and temporary works design.
Do I need training to install a waler frame?
Operatives must be trained and competent, and briefed on the temporary works design where one applies. The system itself is straightforward: connections are pins, R-clips and M10 bolts, and each frame goes together the same way. Safe use instructions and the user guide are available for all our waler kit, and if your crew haven't used the system before, talk to us for a free consultation.

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Questions? Talk to SEL about Aluminium Waler Frames

Our team is responsive, experienced and happy to help.