Saudi offshore support vessel operator Hadi Hamad Al-Hammam is experiencing improved uptime for a seven-year-old vessel, after replacing its original shaft seals
Hadi Hamad Al-Hammam reports the original shaft seals fitted to Hadi 37, a 2013-built twin-screw offshore tug supply vessel (OTSV), began to leak and vibrate, resulting in regular visits to drydock for costly repairs.
“The vessel’s existing arrangement did not perform as expected and for a vessel under charter to Saudi Arabian oil major Saudi Aramco, finding a system capable of reducing off-hire time was crucial,” said Ocean Power International managing director Rafid Qureshi. Mr Qureshi said Hadi Hamad Al-Hammam approached Ocean Power International, a Dubai-based engineering and technical services company, to source a more cost-effective solution.
As a result, Thordon Bearings TG100 seals were selected for the OTSV. TG100 are mechanical seals, specially developed for 86 mm to 305 mm water-lubricated propeller shafts typical of OSVs, workboats, dredgers, tugs and other coastal vessels operating in either clean or dirty, abrasive waters.
The primary seal uses hard-wearing, silicon carbide faces and Thordon’s proprietary elastomeric bellows to provide “an unlimited shelf life compared to rubber-based bellows, which need periodic replacement,” said Thordon. The system also incorporates a secondary seal that provides emergency “return to port” capability in the event that the primary sealing surface is damaged.
“Reducing the maintenance spend associated with the original seal installation was the driving factor behind the decision to retrofit Thordon Bearings’ TG100 seals,” said Mr Qureshi.
“Hadi Hamad preferred the maintenance-free seal over other known brands. The costs of pulling a shaft and replacing a seal every 2.5 to 3 years can go upwards of US$35,000 – US$50,000 over the life of a vessel, which is well above the acquisition cost of a maintenance-free alternative,” said Mr Qureshi.
“The owner already had experience with Thordon products aboard the 48-m OTSV; water-lubricated XL propeller shaft and SXL rudder bearings were fitted in 2013 as newbuild installations, so retrofitting the TG100 was an easy decision to make. We installed and commissioned a pair of 165-mm diameter seals at the Dubai Maritime City drydock, in 2016.”
During Hadi 37’s most recent classification survey, Hadi Hamad Al-Hammam found the seals to be in “excellent working order.”
Hadi Hamad engineering manager Khalid Zahran, said “We recently inspected the seals in drydock and they were in perfect condition. We are highly satisfied with their performance.”