Thursday, May 31, 2012

Buoys Replaced By Structures

Detroit Harbor -

Two of the floating aids in the Detroit Harbor channel, buoys number 4 and 5, are being replaced by permanent structures.  The new aids to navigation will be solid cylinders of steel, cement and stone, anchored by nine H-piles into bedrock, and topped with a steel pole upon which will be a light, solar panel and battery.

This contract, estimated to be in the half-million dollar range, was bid to the Rock company of Pontiac, Michigan.  Door County marine contractor Roen Salvage, of Sturgeon Bay, is the major sub-contractor.  Other subcontractors include the drilling company that bored the holes for the pilings, and suppliers of the buoy cylinders and light towers.

Two of Roen's work barges are shown in the photo here shortly after they began the project.   Pipes of 14" diameter were set into the bottom a the buoy locations, then used as guides as they were drilled out, down three feet into bedrock.  Nine H-piles per navigation aid were then inserted into the drilled holes inside each pipe, and then epoxied into place using a special grout mixed with sand.   The pipes were removed once the epoxy was set

These permanent aids to navigation had been proposed for several years by the U. S. Coast Guard, but funding wasn't in hand until this fiscal year.   The new aids should eliminate drift from station (something that did occur with the older, floating buoys, especially as ice forced against them).  Batteries, solar panels and bulbs can be accessed easily for servicing by Coast Guard Aids to Navigation team members by small boat.  Formerly, a shallow-draft Coast Guard vessel would cross the lake from its home port in Muskegon to lift the floating aids with an A-frame, and its crew would inspect each chain and sinker.  The buoys would then be repainted, with chain replaced, if needed, before being reset on station.  

The tops of the new 12-ft. diameter cylinders will stand approximately 7 1/2 feet above water level, and  have a nearly 20-ft. mast on top of that.  These will make a strong target on radar scopes, and they will also be more easily seen during nighttime or low visibility by vessel operators.  (One of two cylinders is shown in the photo below as it is lifted from the semi to the Roen work barge, alongside Northport Pier.)

Roen Salvage is the largest and oldest marine contractor in the area.  This company typically bids on  marine construction projects such as dredging, break wall and dock construction around the Great Lakes.  From Detroit Harbor, this rig will prepare to sail to the upper St. Mary's River, where several similar, but larger, navigational aids will be constructed.  When that job is completed, the construction equipment will be towed to Duluth harbor at the western end of Lake Superior for another project that will include dredging of 200,000 cu. yds. and driving pilings for commercial shipping.

Actual work on the Detroit Harbor aids to navigation began Monday, May 24, after the equipment had been mobilized to the island. Work is expected to be completed - barring delays in supply of the light towers - by Friday, June 8th.   The steel cylinders that shape the base of the aids and the light pole assemblies are pre-fab items subbed to another company in the Fox Valley.  Delays in receiving those items could possibly prolong the project's completion.

Shown below is Don Sarter, Construction Supervisor and a 39-year Roen employee, who also operates the tug Stephan M. Asher that tows and positions the work barges.

Not yet known, but to be determined soon, is the fate of the dredging application by the Town of Washington for the Detroit Harbor channel.  This application, submitted earlier this calendar year, is believed to have cleared the citizen's committee that reviews such applications.  If so, it now awaits further review for approval by the WISDOT secretary, and finally, approval and signature must be given by Wisconsin's governor.   If approval is given and funding is released, this would mean a huge improvement for Washington Island, a major dredging operation that will widen and deepen a  navigation channel last touched in 1937!

This project could possibly be undertaken yet this calendar year.  However, approval and funding dollars through a Wisconsin Harbor Assistance Program Grant to the Town of Washington must first receive approval in order for any dollars to be allocated.  There were four or five other Wisconsin commercial port applicants, each with worthy projects competing for those same dollars.

-  Dick Purinton


Chuck Sena said...

Interesting info Dick.

Any info why they chose to begin this work now with a pending application for deepening and widening the channel? I am guessing that if they delayed for another year it would not have a huge impact. After all, the other buoys in the turning basin will still need to be serviced and tended the old way won't they? If so the savings seem minimal.

And if widening the channel is approved would either of these aids need to be relocated? I agree that the idea seems to be fairly sound. But I wonder if they aren't doing things out of sequence here.

Richard Purinton said...

Excellent points, Chuck. When "permanent" structures were first mentioned by Coast Guard representatives, I envisioned a few driven pipes, maybe a cluster with some concrete or welded steel holding them together, but I underestimated the massiveness of the planned construction. These aids follow examples of other solid structures engineered and built elsewhere for the Coast Guard, some at expanded scale beyond these. As for location relative to the channel, and possible dredging that might come, aid #5 was adjusted a few feet to better reflect the actual channel. The Coast Guard had been informed of the pending, channel dredging project, and apparently that work, should it go forward, wouldn't interfere with the location of these two permanent aids. There is something to the momentum of a government project, taking a long time to rise to the level of bidding (as it had early last summer), then finally a serious run at getting the job done. I suspect it reflects the dollars available. ** if you or I funded this project we might cut corners drastically, figuring it would be easier to repair and buttress rather than doing the "Cadillac" right off the bat.
I appreciate that Detroit Harbor is getting some attention in terms of navigational improvements, as it has been a long time with "we can get by." ** In a future blog, we may take a closer look at the new Kvichak 45-ft. Coast Guard search and rescue craft recently delivered to its berth here at the island. - DP

Bill Tobey said...

Great info, Dick. I've been watching the Northport activities with the Roen Barge and tug (didn't know who they belonged to) coming and going.

Will these new aids have any audible signature? My perhaps-incorrect memory says the buoys had clanging bells driven by bobbing on the waves.

Richard Purinton said...

No sound devices (neither did the aids they are replacing.)

Tom B said...

Will there be a place for the birds to rest?

Richard Purinton said...

A place for birds to nest, you ask? Should they need this man-made structure, they have the equivalent of a luxury high-rise, rails all around for perfect roosting, resting, viewing, and I wouldn't be surprised at all if a pair of larger birds in the future, such as eagles or ospreys, take advantage of the location. They, there are also those pesky swallows that build mud nests, and they might be at it right now, claiming the underside of the platform as their own. The most challenging, it would seem to me, will be to keep human curiosity seekers off the structures.
- Dick Purinton