What Powers Deck Work and Formwork on a Bridge Rehabilitation?

Deck removal, deck repair, and formwork on a bridge rehabilitation draw power from several kinds of equipment, and a diesel generator is often the shared source behind the electric tools. Breakers, saws, vibrators, pumps, lighting, and welders each ask for something different. Which of them end up on the generator depends on the contract, the scope, and the structure. Planning that list early keeps a crew from stalling on shift because a tool has no feed.

Temporary power on a construction site comes with electrical safety expectations, and OSHA’s ground-fault protection standard is a useful reference when planning outlets. The page states that 120-volt, single-phase, 15- and 20-ampere receptacle outlets on construction sites that are not part of the permanent wiring of the structure and are in use by employees must have approved ground-fault circuit interrupters. It also describes an assured equipment grounding conductor program as an alternative approach to those devices. Your safety lead and contract documents decide which approach applies on your job. The article on where temporary power requirements appear in DOT contracts shows where to look in the contract package.

Stag Power Rentals supplies diesel generators from its Dickinson, TX yard, with a fleet that runs from 20 kW to 2000 kW. Rentals are billed by single, double, or triple shift, so crew schedules on the bridge shape the cost as well as the equipment. The sections below cover tool loads, generator placement, and fuel for deck and formwork work. Treat them as a planning checklist, since each bridge and each contract differs.

Demolition and concrete-removal tools

Concrete removal on a deck can involve electric breakers, rotary hammers, core drills, and saws, along with equipment that runs on compressed air or hydraulic power. Where a compressor or hydraulic power pack is electric, it can become one of the larger loads on the generator. Where it has its own engine, it needs fuel and a place to sit but not a feed. Read each tool’s nameplate or manual rather than relying on a general rule.

Motor-driven tools often draw more current while starting than while running, so the generator needs headroom above the running total. Several tools starting at once makes that gap wider. Stag’s construction site generator sizing and load list gives a structure for collecting each tool’s figures. Bring the nameplate data from your equipment, and the team can review the list with you during the quote.

Vibrators, pumps, and placement equipment

Once the old deck is removed and new reinforcement is in place, concrete placement brings its own power needs. Electric vibrators run from a feed, while some vibrators are engine or air driven, so the type on your crew’s equipment list decides the load. Concrete pumps are often self-powered, but dewatering pumps and smaller transfer pumps may be electric. Confirm the type for every pump the contractor plans to use.

Pour days concentrate loads into a short window, which differs from the steadier draw of demolition. Vibrators, lights, and any electric pumps may all run together during a placement. Add them up as a group rather than one tool at a time.

Lighting, welding, and repair work

Lighting is a small load per fixture, but a long deck or the underside of a span can need many of them. Shift work extends the hours lights run, and double or triple shift schedules extend them further. Work beneath the deck or inside containment may need its own lighting circuits. Count fixtures from the lighting layout instead of guessing. Light towers and generator-fed fixtures for work after dark are compared in the article on lighting and powering a night lane closure.

Welding for repairs, such as steel supports, embedded items, or formwork hardware, depends on the machine. Engine-driven welders carry their own power source, while electric welders draw from the generator and list their input requirements on the nameplate. Those requirements, including phase and voltage, should be matched to the generator before it ships. Ask the welding contractor which type the crew will bring.

Matching tools to power sources

The table below is a planning aid for the conversation between the contractor and the rental team. It lists common deck and formwork items, the power source to confirm for each, and a note on what to watch. It does not give load figures, because those come from the nameplate on the equipment your crew will use. Fill in the blanks from your own equipment list.

Generator placement and access limits

Where the generator sits matters as much as how large it is. A unit on or beside a structure has to fit within the closures, lane limits, and staging space that the project provides. Whether the deck, an approach, or an adjacent area can carry the weight of a unit is a question for the engineer and the contract documents, not a rule of thumb. Ask early, because moving a unit later can mean another lift or closure.

Stag’s towable diesel generators can suit sites where a unit has to be positioned and later repositioned along the work zone. Cable runs can then be shorter than if one large unit stays at the end of the bridge. A power distribution setup spreads the feed to panels along the span so crews are not dragging long cords across the deck. Which layout fits depends on the access the site allows.

Placement questions are easier to settle with a short checklist than in the field. The list below covers what to ask before a unit is staged. Answers usually come from the contractor, the owner’s representative, and the traffic control plan.

• Can the unit sit on the structure, or does it have to stay on an approach or adjacent ground?
• What ground or deck loading limit applies, and who confirms it?
• How will the unit be delivered and removed, and does that need a closure window?
• Where will panels, cable, and cord routes run, and what protects them from traffic and tools?
• Is there a safe, level spot with room for fuel service and for crews to work around the unit?
• Does the unit need to move as the work zone moves?

Fuel logistics

Diesel consumption follows load and run hours, so a deck crew on double or triple shift burns through fuel faster than a single shift crew. Stag’s fuel consumption chart offers a starting point for estimating, and the final figure depends on how heavily the unit is loaded. Rental billing is by shift, so fuel planning and shift planning go together. Estimate from your own schedule rather than from a generic number.

Refueling on or beside a bridge can be harder than at a typical site, because access may be limited by lane closures or restricted staging. A generator fuel tank rental option can extend runtime between fills, which means fewer fuel deliveries disturbing the work zone. Spill containment and who handles refueling should be agreed with the site safety lead. Plan fuel deliveries around the times the site allows access.

Lining up power for your bridge rehabilitation

Stag Power Rentals can help sort the load list, the placement questions, and the fuel plan into one rental request. Start with the construction overview to see how Stag supports contractors, then send the details for your deck and formwork scope through the quote request form. Include tool lists, expected shifts, access limits, and the site location so the quote reflects the job. The team in Dickinson can then recommend a unit from the 20 kW to 2000 kW fleet.