60 feet steel sport fisher with enlcosed bridge

Hello,

I'm new to the forum & boat design. In Egypt, the sport fisher boat designs are almost standard, and the hull material is always wood, between 15-72 ft LOA.





I'm planning to build a steel hull sport fisher (LOA 60 ft/Beam 19.685 ft), with complete wooden surface (deck, bridge & accommodation). I like the Viking enclosed bridge design, with some modifications.



The basic specs would be as follows:
- LOA: 59.0558 ft/18 meter - excluding bow pulpit & stern platform
- Beam: 19.685 ft/6 meter
- Hull Type: semi-displacement /double chine
- Hull Material: steel 0.236 inch/6mm sheets
- Surface Material: wooden deck, bridge & accommodation
- Accommodation: 1 saloon + 4 cabins + 2 bathrooms + 1 deck WC + closed galley + enclosed bridge
- Power: 1 diesel engine (truck modified MAN V6 or Mercedes V10 or Scania or Volvo) +300/+400 hp
- Cruising Speed: 15 knot
- Fuel Capacity: 2641 gallon/10,000 liter / 2 steel tanks
- Water Capacity: 2 ton / 1 fiberglass tank
- Generator: 1 x 25 KW

I'm not experienced with yacht planning calculations & drawing. Is there anybody who can help with this somehow?

Thanks in advance!

Have a nice day,

Hesham Bahi

 

Hesham, welcome to the forum.
I'm sure I could help you and would gladly. If you are concerned, to exchange more information, email me at: 657677483@orange.es

 

A reply by email has been sent to you. My email address is hesham.bahi@gmail.com .

 

Sportfisherman of the American style have a lot of flare in the bow and tumblehome at the stern. To build it in metal, you will find a lot of difficult and expensive fabrication. Usually it gets done by cutting the metal into strips and working them on an English wheel; then welding the strips together.

 

Yesterday, I visited the builders'site; they are really professional & can do all the difficult work even better than the best expectations.



Sorry that I have no better pics.

Please check this video (different builder's boat), too:
https://fbcdn-video-a-a.akamaihd.ne..._=1437590958_88dcb11811b49bb6767c9e3f95d9fa49

 

Check this video, too. You'll like it
https://fbcdn-video-h-a.akamaihd.ne..._=1437592898_bce7d6cff828550b7a628b9e6bc3f650

 

No problems with this type of ships, that a medium shipyard, with a little experience, is unable to solve. I would say even more, these boats have no special problems for any metal boats shipyard.
By the way, Capt. Bahi, quality of steel work, according to what we see in these videos is very high, . Another thing is the process of launching ???

 

I just edited the above main post by adding the following basic specs:

- LOA: 59.0558 ft/18 meter - excluding bow pulpit & stern platform
- Beam: 19.685 ft/6 meter
- Hull Type: semi-displacement /double chine
- Hull Material: steel 0.236 inch/6mm sheets
- Surface Material: wooden deck, bridge & accommodation
- Accommodation: 1 saloon + 4 cabins + 2 bathrooms + 1 deck WC + closed galley + enclosed bridge
- Power: 1 diesel engine (truck modified MAN V6 or Mercedes V10 or Scania or Volvo) +300/+400 hp
- Cruising Speed: 15 knot
- Fuel Capacity: 2641 gallon/10,000 liter / 2 steel tanks
- Water Capacity: 2 ton / 1 fiberglass tank
- Generator: 1 x 25 KW

Any help?

 

I thought American sport fisherman boats where built of wood (I think Gonzo implies he knows this too)... maybe a good wood hull should not be excluded from consideration in this case either.

 

Most sport fishers of this size with decent performance (over 12 knots) use lighter weight materials like wood, FRP, or aluminum - which can also be used for all the structure -hull, deck, cabin, etc.. Using steel could be a challenge and offsetting the weight with lighter materials using secondary attachment could only add to the issue. Some may argue that the costs will be less but keep in mind a heavier boat will require more power to achieve speed and more fuel to achieve the range... both of which add to the weight.
The attached '54' aluminum managed 21 knots with a pair of 300 hp Caterpillars. It is also Transport Canada certified as a passenger vessel.

 

I have built many sportfishermen in wood and composite. Metal is not the ideal material for the shape, but can be made to work.

 

Most North American sportfish boats are built from fibreglass

Coastal Craft from Canada builds an ALUMINUM 65 foot boat that half loaded, ie fuel and water weighs in at about 75,000 pounds.

Your 60 in steel will be a heavy weight if using 6mm thick steel for the hull.

I would hazard a guess that a single 300-400 hp motor will not get this to your planned cruise speed of 15 knots

Steel might be good for displacement boats but may not a good choice for a PLANING hull with only 300-400 hp.

Our old 34 Silverton with twin 300 hp would cruise at 17 knots, it weighed in loaded around 17,000

While many will say that the new coatings make a steel boat feasible and they can be, but by the time that you install tanks, gen sets, and all the other mechanical items into the boat, much of the inside of the hull will not be accessible to check and recoat any corrosion that will occur over the life of the boat.

While aluminum is lighter but more expensive, you gain some economy as aluminum is easier to build with and does not need a bullet proof inside coating to keep it from corroding

And further to savings, the small cost saved going with steel over aluminum will be insignificant when compared to the entire cost of the project

So with aluminum, you save on building costs, internal corrosion protection costs and much more importantly you will save much more than the cost of the differential between aluminum and steel in decreased fuel costs.


Kasten Marine's website discussed the pros and cons of different materials but always keep in mind that often when he is talking about boats, he is often making reference to displacement hulls. And steel for a displacement hull is better than steel for a planing hull.


Sure you can build it in steel, but if it was even remotely cost or fuel efficient, you would see a lot of 60 foot steel PLANING hulls powered by single 400 horsepower motors built by notable boat builders.

Steel weigh about 490 pounds per cubic foot and aluminum 170 pounds per cubic foot. While you need a little thicker hull plating, or more stringers, you will still save maybe 30 40 percent in the hull weight going with aluminum.

 

Does anyone know what the weight of the structure of steel or aluminum, or GRP, or wood ?. What is the percentage of this weight of the total boat ?.
Without such data, I would not dare to tell the Capt. Bahi his steel boat will be a misfortune.
Also, I would assume that he has already previously thought and has reasons to prefer a steel boat.
I think our mission as friendly and willful people and, above all, as qualified technicians, is to tell the Capt. how to build his boat so that even being of steel, is a success.

 

Agreed but:

A Viking Sportfish 66 weighs in at 102,000 pounds.


Tansl, with your European perspective and experience, would you think that you could get a 65 foot steel boat weighing in anywhere in this neighborhood up to a 15 knot cruise with 300 to 400 horsepower?

The OP is new to design and has asked for help.

So for my OPINION for what it is worth

1) Steel for a PLANING is a poor choice due to INTERIOR corrosion problems that COULD occur behind fixed equipment

2) It is unlikely that a steel hull could be built as light as a fibreglass or aluminum boat resulting in poorer performance

3) It is unlikely that you could plane a 60 foot 70,000 to 100,000 pound boat with a single 300-400 hp engine

4) The savings of using steel over aluminum will be consumed by the additional construction costs, the additional interior corrosion costs, the future maintenance costs to prevent internal corrosion, AND more importantly
the additional fuel consumption costs of pushing a heavy boat


Perhaps some contributors can provide some examples of a steel 65 foot boat, cruising at 15 knots with a single 300-400 hp engine.

The Viking 70 runs twin 1550 hp Mans, and I have never seen any GRP, Aluminum or Wood 65 boat running at 15 knots with this low horsepower.


I agree that we should pass our experience onto Capt Bahi in a friendly manner, but also to provide our opinions as to
the practicality of his choice when he has said that he has no
experience in boat building or design.
You will note on his specs that he does not include a weight of the boat. mmmm????

 

Unfortunately, neither fiberglass nor aluminum is an option in Egypt, or the material cost will be dramatic. The only two options are wood & steel, economic wise. In regards to the engine, I decided to amend it to be 2×375hp (approx), based on your & several other friends advice.

No doubt the inner side of steel hull, as well as the steel tanks will be well painted, and I'm willing to use the "sacrificial anode methode" as an additional way to protect the hull.

The estimated displacement would be:
- 50-55 MT in case of 6mm steel sheets for the complete hull
- 45-50 MT in case of 6mm for lower part & 4mm for upper part of the hull