The Sullivan Heavy Timber Bulkhead Project – is unusual in that we used 16′ long 9″ head round piles on 4.5′ centers with 4″ x 12″ stringers. The piling penetration is approximately 7 to 8 feet with the outer layer of sheet-piling penetration running approximately 6 feet on average before the second layer is installed directly behind it.

The project is tied back with 3/4″ x 20′ & 15′ heavy hot-dip galvanized tieback rods, which are nickel carbon steel and threaded on each end approximately 18″ to 24″. The inner washer is a specially machined 3/8″ thick by 4″ diameter round flat washer and the outer washers are special marine grade Hot Dip Galvanized Ogee Washers from Portland Marine Supply, being about 3.75″ in diameter and approximately 1″ thick in the center, they will never fail, bend or buckle at the extra weight that tropical storms can create.

The deadman posts will also have additional cross timbers attached, installed horizontally in front of each post for additional anchoring.

This wall will be incredibly resilient at the waterline, having a .60CCA “pool elevation flotsam & debris deflection sleeve” installed in front of the sheet-piling above and below the normal waterline. This initial layer will last for a minimum of 2 decades before the first sheet-pile layer is finally reached. The sheet-piling layer only then becomes the primary layer, which normally lasts for about 2 decades on the main lake body.

Then finally. that layer is backed up by a second layer of sheet-piling that will add an additional 20 years or so before it finally requires a second sheet-pile back-sleeving.

Since the stringers and piles are so heavy we expect this wall to last longer than any other – probably exceeding the 4 decade mark before replacement.

Even then, all the new owner will have to do is put a 3/4″ coupling on the ends of the tieback rods and use the huge tieback system that exists below ground by adding 24″ all-thread rods to extend the existing system to anchor the new wall.

By pre-designing the tieback system to last longer than a conventional single deadman tieback system, this anchor system can last up to a century below the ground because the dead-man posts will be tar-coated to seal the ends keeping them from rotting, in addition to the anaerobic seal that the clay will create around them.

Excellent design practices can make for long-lasting projects. Shoretech Marine Consulting LLC & Shoretech Marine Construction & Design – “Simply the Best, Guaranteed”