JULY/AUGUST 2017

When the underwater portions of a bridge or waterfront facility need to be inspected, the right person

for the job is often an engineer diver, a specially trained professional who understands load paths in structures and also knows the best ways to avoid contracting "the bends." Working under conditions

that can include zero visibility, strong currents, thick ice, and alligators, engineer divers must confront physical challenges far more daunting than those faced by most civil engineers. By Robert L. Reid

NGINEER DIVERS ARE CNIL ENGINEERS who wear wet suits to work. Or they wear so-called dry suits or

other underwater outfits. They don hard helmets that are connected to hoses that supply them with breathing air

from the surface and provide a communications link while they are underwater. Sometimes they even strap

scuba tanks to their backs as they dive down to investigate the con-ditions of underwater structures. They may be examining bridge piers or the foundations of bridg-es that cross bodies of water. Or they may investigate the under-water components of such water-front facilities as pile-supported piers extending from the shore-line, wharves, sheet-pile bulk-heads, dry docks, mooring dol-phins, and floating structures. Sometimes they even examine the hulls of ships or the bottoms of waterways themselves.

Although the idea of div-ing underwater for work might seem like a pleasant day at the beach to many-and in truth, plenty of engineer divers are or have been recreational divers in their spare time----the skills and experience required to conduct underwater inspections are con-siderable, as are the challenges and hazards. From trying to as-sess structural damage under conditions of near-zero visibility to struggling against strong cur-rents, from diving underneath ice thick enough to stand on to sharing the waters with snakes, alligators, or even sharks, engi-neer divers often work in an en-vironment dramatically different

the late 1970s, notes Charlie M. Roberts, P.E., D .PE, M.ASCE, a project manager at Childs Engineering Corporation, of Bellingham, Massachusetts, which was a pioneer in the en-gineer diver field. But tragically, the origins of the engineer diver field as a bridge inspection niche within the civil engi-

neering profession largely grew out of a pair of bridge failures in the 1980s, one the April 1985 collapse of a bridge over Chick-asaw Bogue Creek near Mobile, Alabama, which injured one mo-torist, and the other the collapse in April 1987 of the Schoharie Creek Bridge, near Fort Hunter, New York, in which 10 persons died. In both cases the bridge col-lapse was linked to damage that was out of sight and underwater. The result, especially from the Schoharie deaths, was "a wake of public concern about underwater inspection of our bridges," wrote Thomas J. Collins, P.E., S.E., D.PE, F.ASCE, then the president of Chicago-based Collins Engi-neers, Inc., in "The Wet Look," an article in the September 1987 issue of Civil Engineering.

"In the past," noted Collins, now the firm's executive chair-man, "many waterfront struc-tures have not been inspected underwater, because the process was considered too expensive and unnecessary." Indeed, in 1985 only 24 states had programs for underwater inspections of bridge foundations, according to "U.S. Opens Hearing on Un-safe Bridges," an article by Wil-liam E. Schmidt that appeared in the New York Timeron)uly 18, 1985. After the Schoharie col-

from what most civil engineers will ever experience.

The U.S. Navy has been working with engineering firms to inspect the underwa-ter portions of its waterfront facilities since

Roy A. Forsyth, P.E., C.H., a diver and structural engineer at Collins Engi-neers, helped inspect the underwa-ter portions of the Chesapeake Bay

lapse, however, the Federal Highway Ad-ministration (FHW A) "strengthened its un-derwater inspection policy," Collins wrote. "Underwater programs spawned follow-ing [an} FHW A memorandum stressing the Bridge-Tunnel in February 2014.

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need for 'hands-on' inspection .... Since then, every state has either established or is in the process of establishing an underwater inspec-tion program."

During underwater inspections, engineer divers document

such damage as severe corrosion in steel pipe piles.

tion training course or an FHW A approved underwater diver bridge inspection train-ing course."

Collins Engineers was an early participant Moreover, since 1988 the FHW A, through

the National Bridge Inspection Standards (NBIS), which set the minimum requirements for inspections and evaluations of all highway bridges in the United States, has "required that the submerged elements of all bridges with substruc-tures located in water be inspected at regular intervals not to exceed 60 months," according to Underwater Bridge In-spection, a June 2010 report that Collins Engineers prepared for the FHWA. "Bridge owners must prepare and maintain an inventory of all bridges subject to the NBIS, and must identify all bridges requiring underwater inspection," the report noted.

If a bridge requires underwater inspection, the bridge owner "must identify the location of underwater elements, including a description of the underwater elements; establish the inspection frequency and the procedures for conducting the inspection of each bridge requiring underwater inspec-tion; and conduct the inspections of those elements requiring underwater inspections according to those established proce-dures," explained the report.

The report also noted that "in accordance with the NBIS, owners must identify all bridges that are scour critical, i.e., bridges with a foundation element that has been determined to be unstable for the observed or evaluated scour conditions. Since 2005, the NBIS has specified that a qualified team lead-er must be present at the bridge for all underwater bridge inspections, and all inspection divers must have successfully completed an FHW A approved comprehensive bridge inspec-

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in inspections by engineer divers, and Collins himself helped author various texts on the topic, including the FHWA report Underwater Impection of Bridges, published in November 1989; ASCE's Underwater Investigations: Stan-dard Practice Manual, published in 2001; and the June 2010 FHW A report Underwater Bridge Impection. The ASCE manual, sponsored by ASCE's Coasts, Oceans, Ports, and Rivers Insti-tute, was edited by Kenneth M. Childs,Jr., F.ASCE, now de-ceased, the founder of Childs Engineering.

Although not all firms that provide underwater inspec-tions use divers who are civil engineers, the benefits of sending down men and women with engineering experience are clear, notes BryanN.Jones, P.E., D.PE, D.CE, ENV SP, M.ASCE, the northeast ports and maritime leader in the Boston office of the international engineering firm HDR. The difference between an engineer diver and someone who is simply a good diver but not an engineer involves "understanding the structures that you're evaluating, understanding the load paths in the types of construction, and as the structure deteriorates, [knowing} how those load paths change," explains Jones, who does not perform underwater inspections in his current position. Previ-ously, though, he worked for eight years as an engineer diver for Collins Engineers and nine years as an engineer diver for Ocean and Coastal Consultants, Inc., now part of COW! Ma-rine North America, which has its headquarters in Seattle and North Vancouver, British Columbia.

Jones also chaired a committee within ASCE's Coasts, Oceans, Ports, and Rivers Institute that spent roughly a decade working

to establish a formal diver training standard for engineer divers, an effort that ultimately "fell apart" in 2016 because of opposi-tion from the commercial diving industry, Jones notes. Many engineer divers learn how to dive through commercial diving programs, he explains, but those programs are focused on un-derwater construction, primarily for offshore industries, and cover certain tasks that engineer divers are unlikely to perform, for example, underwater welding. Still, it ultimately proved too difficult to create a standard aimed expressly at engineers as op-posed to continuing with the better-known commercial diving programs,Jones concludes.

With their knowledge of structures, though, engineer divers represent a sort of "one-stop shop" for their clients, notes Mike Ajemian, P.E., the New England practice leader in the Braintree, Massachusetts, office of COWI Marine. "We can go out in the field and perform the inspections," Ajemi-an explains. "Then we take whatever information we see in the field, come back in the office, and the same person that was doing the actual inspection can write the structural con-dition assessment report or they can develop the rehabilita-tion drawings or the design drawings for the things they saw in the field."

Scott Branlund, P.E., S.E., M.ASCE, a senior project man-ager and diving officer for BergerABAM, which is based in Federal Way, Washington, adds, "We understand how a structure performs, and so we know where to look underwa-ter for distress [that} is considered significant, which can alter the structural performance, and distress [that} is not neces-

The tools of the trade for engineer divers include the Bathycorrometer, used to determine whether a

cathodic protection system is working properly.

sarily significant, even if it might be noted and observed on subsequent inspections." Such low-level distress might not require immediate repairs, which are very costly compared with repairs above the su