How are Bids calculated?

Hi-

I was wondering if anyone would have any idea what the cost per ton is when estimating the cost on say a large tug boat? Any tips in this area would be helpfull.

Thanks

 

Cost per ton for new steel construction will vary depending on locations & local labour rates. Shipyards in China, India & far east may offer considerably lower prices compared to European and American Yards.

Price of Steel material has drastically increased over last 3 years. Now marine grade mild steel will cost ~$750/ M.Tons while purchasing directly from Mill. Cost of labour, consumables, cranage etc. are variables depending on locations. Average "cost" for an efficient shipyard to new construct will be around $1500-$1800 per M.Ton in China, India & Far East. Adding shipyard profit margins & other overhead costs etc, you will pay $2500 - $3000 per M.Tons for new construction at a far east shipyard.

Above is only the Steel part, which may not be a major cost component for small vessels like tug (~20% of total cost). Cost for Machineries, Electrical items, Piping, Outfits, Flooring, paneling, surface treatment & painting, navigation & communication equipment etc. etc. need to be worked separately.

 

Thanks for that information!

I guess I could do a percentage cost comparison on the $750 Metric Ton to try and come up with a figure for building costs in the USA.

How would you do the basic build sequence say on a 150’ steel tugboat? Would you build the main deck upside down first adding the frames and bulkheads then the hull skin before you flip it back over? Any info regarding this would be great.

 

The building sequence will vary depending on shipyard facilities. Basic principle while deciding the building sequence shall be to

Maximise the prefabrication of panels at the Shop. This will ensure better quality, Safer and economic job.

Maximise the downhand welding. Downhand welding will be easier, economic and ensure better quality compared the overhead welding. This is the basic reason why entire deck and stiffeners are welded upside down. Similarly, Side panels, bottom panels, Bulkheads etc may be pre-fabricated separately in blocks and finally they can be assembled together in a Dry-dock or Slip-way.
The size of each pre-fabricated blocks/panels is decided based on Cranage capabilities of the Shipyard. This will also help us to reduce the time required at the dock space / slipway (A busy shipyard will always try to reduce the dock occupancy)

 

Yes good idea welding some of the frames and stiffeners to hull sections flat then put them in place and hope that they don't distort to much from the welding heat. At what point do you think the motors would get put in? and what other key or large components would have to be placed in location of say a large tugboat is the motor or the shaft the biggest thing to go inside?

 

You may leave certain panels at maindeck or sides to be welded after (you may leave them as access) bigger machineries (Main Egine, Generators, shafts etc) are taken in to Engine room. You may use Engine room Skylight for smaller equipment.

 

Ok one last question if you don't mind; the above figures just for my own clarification are for the main structural fabrication and welding. So then I would think there is the additional cost of the Main Egine, Generators, shafts, piping, electrical etc. and is there also new labour hours added on this stuff as well?

 

Ofcourse, you need to add them.