Green Cove Springs: A Bridge Job at the Edge of Town

The new St. Johns River bridge

The design-build team of WGI, Johnson Bros. and American Bridge is building the First Coast Expressway's river crossing just south of the existing two-lane span. The new bridge carries four lanes plus shoulders and a shared path, and its vertical clearance over the channel goes from 45 feet to 65 feet, matching the Buckman Bridge downstream. When it opens, the old Shands Bridge is to be cut back into fishing piers rather than removed entirely.

Long water crossings are built from trestles and barges: crawler cranes walking out on temporary work platforms, marine cranes setting piles and caps, and heavy picks for beam and segment placement. An operator on that job has to understand how capacity changes on a barge, how wind on a long girder affects control, and how to work with a signal person who may be on a different deck.

Reynolds Park, a Navy waterfront turned industrial park

The Navy opened Naval Air Station Lee Field here in 1940; it was later renamed Naval Air Station Green Cove Springs. After the war, 13 piers were built along the west bank of the St. Johns for a reserve 'mothball' fleet that numbered in the hundreds of ships. The base closed in the early 1960s, and in 1965 the property was sold to J. Louis Reynolds for development as a large industrial park.

Today the site holds the Clay County Port, Reynolds Industrial Park and a small airfield, and a 2012 redevelopment plan aimed to turn it into a mixed-use center beside the expressway. Pier repairs, marine construction and industrial tenants bring occasional crane work to the old base.

Hurricane season on a river job

A bridge site in the middle of the St. Johns is exposed from every direction. Under section 489.1132 of the Florida Statutes, a tower crane, hoist or covered mobile crane on a construction site needs a hurricane preparedness plan kept on site, and the contractor in control has to secure it no later than 24 hours before hurricane impacts are expected. The statute's mobile crane definition leaves out cranes with a boom shorter than 25 feet or a rated capacity under 15,000 pounds.

For an operator, that means knowing the boom-down and tie-down steps in the manufacturer's high-wind guidance and being available when the call comes to lay the boom over.

Questions to answer before you set up

• Is the crane on a barge or trestle? Then floating-crane rules in 29 CFR 1926.1437 and the manufacturer's list and trim limits apply.
• How close are energized lines along US 17 or the river crossing? Work out the 1926.1408 clearance before the boom goes up.
• Is the ground fresh fill or riverbank sand? Size mats for the outrigger load, not the crane weight.
• Who is the signal person, and do they have line of sight? Agree on hand signals or radio channel before the first pick.