INDUSTRIAL TEMPORARY BRIDGES INSTALLATION – a checklist…

EQUIPMENT NEEDED

Crane or boomlift: Remember it must be able to comfortably reach the center of the temporary bridge span while NOT sitting at the very edge of the ravine or creek. A crane + an industrial modular bridge = a very heavy load. You don’t want your equipment sliding down an embankment.
A level or transit and string lines: To check for a smooth base.
Proper PPE: Hard hat, steel-toe boots, leather gloves.
Proper lifting equipment: Lifting chains, heavy-duty slings with clevis hooks, etc. Double-check the load ratings on all equipment before installing your portable bridge.
A crew: At least 5–6 people, and more depending on the structural size of the project.

DELIVERY OF YOUR PORTABLE BRIDGE

It sounds simple, but don’t forget to have a clear staging area for your portable bridges when they arrive on site. That flatbed truck isn’t going to sit there all day waiting for you to unload. If you are deep in the woods for a logging or construction project, be sure to clear a staging area ahead of time.

SITE CHECK

Make sure the gravel-timber foundation base is perfectly level and has no bumps.
Take a can of spray paint and determine exactly where the temporary bridge will sit, then mark this out on the ground. Do not attempt to eyeball it!
Look around—watch carefully for any overhead power lines, buried utilities, fences, designated trees, or other objects that could be damaged during the construction process.

SETTING THE MODULAR BRIDGES IN PLACE

Your structural modular bridges will have D-rings in the center and at each end for lifting, dragging, or skidding.
It’s ok to drag or skid the bridge components on the ground; just make sure any connecting pins or box beams are not damaged.
NEVER use a guardrail as a lifting or dragging point.
For the pin-connected, smaller portable bridges, set the middle section first—then set the other two sections in place over the pins.
For the heavier-style modular bridges with the box beam inserts, set the bridge sections in place according to their numbers (1-2-3). Make sure the ends align perfectly. Then, insert the I-beam connections into the box beams while working from the center one out. These can require a bit of persuasion because the fit is tight. Use plenty of grease on the beam. The boom crane may need to nudge them into place.
NOTE: Do not damage or bend the pins, box beams, or I-beam inserts in any way. Do not lift or drag any temporary bridge section by these structural components.

DANGERS TO WATCH FOR!

Be aware of soft embankments that can crumble or give way suddenly, especially with heavy equipment and loads nearby.
Never attempt a portable bridge installation alone.
It’s important to never be underneath any part of the modular bridge sections while they are being set in place. Crouch down and look for alignment from a safe distance.
Watch for frosty surfaces! Bridge surfaces, ground surfaces, unloading ramps—all can get slick with a coating of frost.
Watch for pinch points—bridges need to be pushed into place. Never, ever grab the mating side of a portable bridge that is being lowered and aligned with an adjoining section. Always push or pull from a free, safe side.
Consider fall protection if you are working over deep water, a steep ravine, or very fast-moving water.
Power lines: Many people forget that high voltage can jump many feet through open air to a crane boom. If you are using chains, this electrical charge can move into the entire steel section of the temporary bridges you are setting and create a deadly charge for all nearby workers.

The industry-standard rule for crane operation around power lines is dictated by OSHA Standard 1926.1408 (Table A).

The Standard OSHA Clearance Chart

Voltage (Nominal, kV, Alternating Current)	Minimum Clearance Distance (Feet)
Up to 50 kV	10 feet
Over 50 kV to 200 kV	15 feet
Over 200 kV to 350 kV	20 feet
Over 350 kV to 500 kV	25 feet
Over 500 kV to 750 kV	35 feet
Over 750 kV to 1,000 kV	45 feet