Thordon Bearings, of Burlington, Ontario, Canada, has received an order to supply four comprehensive shipsets of stern gear for a new class of towboat.
The four boats are being built by US shipyard Master Marine of Bayou La Batre, Alabama, for Waterfront Services, based in of Cairo, Illinois. The new vessels have been designed to meet the requirements of Subchapter M, a set of federal rules recently introduced by the US Coast Guard, relating to the inspection requirement for towboats, including seaworthiness standards and safety protocols.
The 20 m x 8.5 m boats, each powered by twin S6R2-Y3MPTAW Mitsubishi diesel engines, rated at 599 kW at 1,400rpm, will drive 70in x 48in x 7in four-blade, stainless-steel propellers through Twin Disc MG 5321 gearboxes with 5:1 reduction ratio.
Thordon has been contracted to supply its RiverTough propeller shaft bearings for a 6in diameter shaft, along with hardened shaft sleeves, SXL bearings for main and flanking rudders, TG100 tailshaft seals, and happy to be teaming up with Waterfront
Services to provide these latest fleet
boats with the best heavy-duty
equipment available that’s capable of
meeting Subchapter M requirements,” he
The first two vessels in the series,
Miss Deborah and Tom Toretti, have already
been handed over, in October 2017 and
January 2018, respectively. The remaining
two, Sam P. Hise and Rick Pemberton are
scheduled for delivery in April and July
Thordon’s RiverTough water-
lubricated bearings were developed
specifically for use in abrasive-laden dirty water such as that found in the
Mississippi River system. When used in
combination with hard-coated nickel-
chrome-boron (NiCrB) shaft sleeves and
a TG100 shaft seal, the arrangement can
last twice as long as the rubber bearings.
The TG100 tailshaft seal uses high-
quality, hard wearing silicon carbide faces
and Thordon’s proprietary elastomeric
polymers to offer the optimum
combination of strength/stiffness and flexibility/elasticity. The seal requires no
routine maintenance, and although
designed for abrasive conditions, it is
equally at home in clean water.
“These new Waterfront vessels have
the complete Thordon riverboat
package,” said Bright. “The scope of
supply includes SXL rudder and
ThorPlas-Blue steering linkage bushings.
SXL has excellent friction resistance,
with operating pressures up to
12N/mm2 (1,740psi). These bearings can
also withstand the high shock loads and
edge loading typical of tow-boat
operations. What’s more, like the
ThorPlas-Blue bearings, they completely
eliminate the need for grease and
greasing systems, removing any risk of
ThorPlas-Blue bearings, designed for a
life-time of grease-free lubrication, are
typically specified to replace the greased
bronze bearings in virtually all steering
and deck machinery applications. Since
these bearings require no maintenance,
the commercial advantages are obvious.
“Thordon’s range of river towboat
systems offers outstanding
wear life in abrasive waters.
Any extra up-front cost is
quickly offset by longer wear
life and reduced main-
tenance down time over the
life of the vessel,” said Bright.
ABOUT THORDON BEARINGS
A respected supplier of
propeller shaft bearing
systems, with over 35 years’
experience in this
Bearings is renowned for supplying high
performance, oil and grease-free bearing
systems to the global marine, clean
energy, pump and offshore markets.
Thordon Bearings is the only
manufacturer of propeller shaft bearings
to guarantee its award-winning
COMPAC system for a 15-year wear-life.
Thordon systems and bearings are
available worldwide through over 80
agents and distributors.
ThorPlas Blue steering
“These are fleet boats, operating virtually 24/7 on the Mississippi River,” explained Jim Bright, Thordon’s USA Business Development Manager. “They are operating in very abrasive water conditions, frequently running close to the river banks in shallow depths.
The customer has previous experience of Thordon
products, with some boats having
clocked up 60,000 to 70,000 hours of