In brief
- A low trench access bid usually means shoring, dewatering, edge protection or reinstatement has been left out, not that the work is cheaper.
- Ask every bidder for a written method statement naming support type, ladder positions, spoil distance and who inspects before entry.
- Price temporary works as a measured line item and confirm ground conditions and any permit requirements with the municipal engineer's office before award.
Contents
Trench access underbidding risks in Qardho show up when a bid prices the digging but not the way workers get in and out safely. The rate looks low because support, dewatering, edge protection and reinstatement have been left out, and the gap only appears once the trench is open.
What does a low trench access bid leave out?
A low bid usually omits the temporary works that make the trench usable, not the excavation itself. Shoring or battering to a safe angle, a ladder or ramp fixed at the correct spacing, edge protection, a spoil bank set back from the lip, and water control are all separate activities with their own labour, materials and time.
Estimators working from a drawing alone can miss these because the drawing shows the finished pipe or cable, not the open cut. If a bidder has not walked the line, they may also miss hard ground, existing services, or a restricted working width that forces hand digging and a longer programme.
Trench support depth rules and spacing are general practice, not local regulations. Confirm the required support type against the project specification and the engineer's instructions, and confirm any permit conditions with the municipal engineer's office before work starts.
How does the gap turn into unsafe excavation entry?
When support and access are not priced, the crew either absorbs the cost or drops the item, and dropping it is the cheaper choice on site. That is how unsafe excavation entry appears: a vertical face with no support, a ladder that is too short or too far from the work face, spoil piled at the lip, or a worker lowered on the bucket.
Water makes this worse. Water entering an open trench, from any source, can soften the faces and the base, and a face that looked stable may not be. Water at the bottom also hides the base and makes the ladder footing unreliable.
A supervisor can detect the risk before entry by walking the open length and checking four things: the support or batter against the method statement, the ladder position and tie-off, the spoil distance from the lip, and the water level. If any of these is missing, stop entry and get the temporary works priced and built.
How do you close the gap before award?
Close it by making every bidder price the same temporary works schedule, then comparing those lines rather than the total. Issue a priced schedule with separate lines for excavation, support, access, dewatering, edge protection, backfill and reinstatement, and require a method statement with each bid.
Ask each bidder to state in writing the support type and depth range, the access method, the water control plan, the spoil location and the name of the person who inspects the trench before entry. Then check what the contract allows for variations, because ground conditions that differ from the assumptions may need a priced change rather than an argument.
If the ground is unknown, ask the relevant authority or project engineer whether any borehole logs or service records exist for the plot, and price a trial pit before the main excavation. A trial pit is cheaper than rebuilding a collapsed face.
What to do next
Before you award the trench package, send every bidder the same temporary works schedule and ask for a written method statement covering support, access, dewatering and inspection. Then walk the line with the municipal engineer's office, confirm any permit conditions, and compare the temporary works lines, not just the totals.
Frequently asked questions
Should a trench access method statement be required with the bid?
Yes. Ask for it with the bid so you can compare support type, access method, water control and inspection arrangements before award, not after the trench is open.
Who inspects a trench before workers enter in Qardho?
Confirm who carries out the pre-entry inspection with the project engineer and the municipal engineer's office before work starts, and keep a record of each inspection.
How do I check ground conditions before pricing trench access?
Ask the relevant authority or project engineer whether any borehole logs or service records exist for the plot, and price a trial pit if the records are missing or unclear.
Local reporting: this article is written for building work in Qardho and Puntland. Ground conditions, prices and rules differ between places; confirm the details for your own site.