Thai Aluminum: Shape and Weld

by Alan Haig-Brown
One of the 18-meter catamarans at work on the Chao Phraya River

 When Khun Namchai Sakunchoknamchai was seven years old he like cars. So he built himself one out of wood. Decades later, he was building those big beautiful custom tour buses that are a feature of Thai roads. When he wanted a 30 million baht machine for shaping rolled aluminum sheet, he designed and built one for less than nine million THB. This machine is just one of the impressive array of technologically sophisticated machines at his factory in Suphanburi, Thailand.

One of Sakun-C’s 19-meter mono-hulls at work on the Chao Phraya River.
One of Sakun-C’s 19-meter mono-hulls at work on the Chao Phraya River.

Recently, he has added an aluminum boat building company, Sakun C, to his ever-growing operations. Utilizing machines like the computer-controlled, 2000-ton press that he uses to shape bus panels, the team is able to shape the side panels for the twin hulls of the 18 by 6.2-meter catamarans that he is building for the recently formed Chao Phraya River Line. This results in a pair of hulls with virtually no vertical welds for greater beauty and strength but also for ease of fabrication.

Another of the 19-meter mono-hulls taking shape in the shop.
Another of the 19-meter mono-hulls taking shape in the shop.

The firm hires untrained workers and trains them in-house to their exacting welding standards. The each side of catamaran hulls has two panels that are joined by a lift strake that becomes a splashguard toward the bow. A welder, using the latest technology, runs a perfect bead the full length of the hull. Other welding of the extruded beams that, are shaped into frames, is done by several highly accurate robot-welders.

The computer-controlled, 20,000-ton press for shaping aluminum panels.
The computer-controlled, 20,000-ton press for shaping aluminum panels.

The result is a handsome commuter ferry that carries passengers to and from shopping malls along the crowded waters of Bangkok’s Chao Phraya River. With a capacity for 100 passengers inside on the main deck and another 20-passengers up-top. Passengers on the upper deck are accommodated on aluminum bench seats fabricated by Sakun C from panels made by their own extruding machine.

Welding the pressed hull panels together for a new catamaran at the ship in Suphanburi, Thailand.
Welding the pressed hull panels together for a new catamaran at the ship in Suphanburi, Thailand.

Each of the hulls is fitted with a Cummins NT855 engine producing 400 HP each at 1800 RPM. The engines turn conventional propellers through Dong-I gears with 2.51:1 reduction. This gives the catamaran a comfortable river speed of 12 knots and a maximum speed of 21 knots . As of early April 2019, there were three of these practical vessels in operation and one in build.

Left to right, R&D Patdanai Satapattayanont, Managing Director Namchai Sakunchoknamchai, Secretary Doungporn Pimsin with catamaran model
Left to right, R&D Patdanai Satapattayanont, Managing Director Namchai Sakunchoknamchai, Secretary Doungporn Pimsin with catamaran model

In addition to the catamaran, Sakun-C has modified the design of one of their fast 19-meter mono-hulled tourist boats for the Chao Phraya River Line. A number of these boats have been built for domestic and export customers. Typically they are fitted with four 250 HP outboard motors, but for the river, where less speed is allowed, the hull bottom was slightly modified to match a Cummins diesel inboard. The river boat is powered by a single Cummins QSB6.7 diesel producing 245 HP to a conventional propeller for a light boat speed of 15 knots.

Capt. Somsal Sakeanok at the helm of one of the new catamarans.
Capt. Somsal Sakeanok at the helm of one of the new catamarans.

Chao Phraya River Line’s founder Cdr. Parinya Ruckwatin, with a background that includes ten years in the Royal Thai Navy, is excited about the potential for expansion of passenger services. In time these will include the shuttles to the five-star hotels along the river and service for the increase to eight landing stations that will interface with the city’s growing sky train system. Speaking of the new ferries he says, “Chaophraya River Line Company Ltd. is a boat transport company which operates on the Chao Phraya River. Since out mission is to provide enhanced services and ensure highest safety standards, out boats are therefore designed to include high-quality equipment and modern communications technology has been integrated into daily operations. This allows our passengers to experience a safe, professional and reliable transportation service. We will dedicate ourselves to constructively improving all aspects of our operations to achieve high efficiency and developing new services to accommodate emerging passengers’ needs, with a determination to become the leading boat transport company on the Chao Phraya River in the near future.“

Cummins marine sales manager Sathit Suwanprasert checks one of the NT855s with an owner’s representative. Engines are accesses by moving a set of seats.
Cummins marine sales manager Sathit Suwanprasert checks one of the NT855s with an owner’s representative. Engines are accesses by moving a set of seats.

As each boat is finished, Sakun C owner and managing-director Khun Namchai Sakunchoknamchai has everyone involved in building it take a river cruise. This is not only a reward for the workers but it lets them experience the importance and the life of what they have built.

The Chao Phraya River is one of the world’s most spectacular river passages.
The Chao Phraya River is one of the world’s most spectacular river passages.

Photos courtesy of Haig-Brown/Cummins
 
For further information:
 
Temduang Phadungsuntararuk
Sakun-C
52/2 Moo 2 Talingchan-Suphanburi Rd.
T. Takha A. Bangplaman Suphanburi 72150,
Thailand
E-mail: cmo@sakunc.com
Mobile Phone: +66(89)991-6566
 
Doungporn Pimsin
Secretary
Sakun-C
52/2 Moo 2 Talingchan-Suphanburi Rd.
T. Takha A. Bangplaman Suphanburi 72150,
Thailand
E-mail: psc@choknamchai.com
Mobile Phone: +66(81)942-0830
 
Cdr. Parinya Ruckwatin
Founder
Chao Phraya River Line
Phone: 087 445 9324
E-mail: parinya@chaophrayariverline.co.th
 
Jennifer McQuilken
Marketing Communications, Marine and Oil & Gas
Cummins Inc.
4400 Leeds Ave. Suite 300
Charleston, SC 29405
E-mail: Jennifer.McQuilken@Cummins.com
Phone: +1 843-696-9534 (call or text)
 
Alan Haig-Brown
A. Haig-Brown & Assoc. Ltd.
Bangkok
Thailand
E-mail: alan@haig-brown.com
web: www.haigbrown.com

Alan Haig-Brown

Alan Haig-Brown

Over 30 years as an author for global commercial marine and fishing publications backed with hands-on experience on commercial fishing boats and coastal freighters makes Alan Haig-Brown uniquely qualified to provide vessel reference articles for Cummins Marine. You can find him in shipyards around the world, and on his own website, www.haig-brown.com.

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