Thordon Bearings’ T-BOSS finds space to grow

The T-BOSS solution will incorporate the company’s successful COMPAC sea water-lubricated propellor shaft bearing with the elimination of the stern tube. Replacing traditional oil-lubricated stern tube bearings brings substantial savings as well as environmental benefits, according to Thordon.

T-BOSS aims to broaden the potential appeal of sea water lubrication further. It replaces the conventional sterntube cooling tank with a dry chamber that is big enough for surveyors or engineers to stand up in; to inspect the non-metallic bearing and seal from inside the ship whilst afloat. “I really, really believe the T-BOSS system is the biggest ship design intervention in the last century,” enthuses Carter, speaking of his company’s revolutionary sterntubeless propeller shaft system design. He adds: “I think it’s going to happen this year,” in relation to a first T-BOSS order.

The new space is accessed through an opening into the bulkhead and will allow for inspection and maintenance to take place without needing to withdraw the shaft. An owner avoiding drydocking would save on maintenance, but could also earn by extending the charter – which could amount to tens of thousands of dollars per day.

The appetite for the T-BOSS system appears to be there. Carter says: “In the last 10 months I’ve met about 80 shipowners all of whom think T-boss is a good idea. The issue is with shipyards and full order books. It’s a shipbuilders’ market at the moment.”

Given the fundamental nature of a propellor shaft to a vessel, T-BOSS has been developed for newbuilding applications and can’t be retrofitted. Carter concedes that there is a degree of conservatism amongst some of the larger shipyards, and adds that Thordon Bearings has hired a consultant to illustrate the benefits of it to them.

The company is joining the voices to influence newbuild decisions away from oil-lubricated sterntubes, enabled by the more commercially and environmentally favourable T-BOSS sterntubeless ship design, says Carter.

“I’m trying to get this consultant to give a side-by-side newbuild cost comparison of a ship with a sealed oil lubricated sterntube versus a ship with an open sterntubeless ship and a single seawater lubricated tailshaft bearing. Then we can go sit down with a shipyard and say to them, ‘This should save you money in labour and material costs’.” The savings come about due to the lack of a sterntube, a singular seal and bearing as opposed to two of each with the oil system, he adds.

Carter acknowledges that some builders in Asia may simply be resistant to change due to their preference for domestically sourced parts for their vessels.

“Independent yards seem to be much more open to innovative technology,” states Carter, adding that the participation of ABS in T-BOSS, and the class society’s award of AIP to CSSC-SDARI, has aided the cause.

ABS’ involvement in the project dates back to 2018 when Thordon founder Sandy Thomson and engineering director Ken Ogle met with Dr. Chris Leontopoulos, vice-president, technology, EMEA, at ABS. Maritime industry partners CSSC-SDARI, the National Technical University of Athens (NTUA) and Wärtsilä Shaft Line Solutions were added to further develop the solution. The T-BOSS revolution has begun.

The voyage of the T-BOSS has tacked through some interesting waters along the way, says Carter; “The design has changed significantly since we first came up with it. Originally one part was a stern space completely full of water!”

Whatever the refinements made along the way, the potential cost savings available to shipowners compounded by the environmental benefits of seawater lubrication suggest that the T-BOSS era may well be soon upon us.