can you decrease plate thickness or use FC for a tug?

Discussion in 'Boat Design' started by tugboat, Apr 17, 2010.

  1. apex1

    apex1 Guest

    Too bad you cannot delete your threads, I agree!


    in proper English it would be: ....need on this site is a "block thread starter button".....

    Before you again dish out your childish rant about my lack of contribution to your childish threads, go a few pages back and read what you find there:

  2. dskira

    dskira Previous Member

    At one moment, the thread talk about finances.
    It is the first reason why builder do not finish the boat.
    A very thorough estimate, and then a clear view of the personal finances is important.
    To have the money, the total cost upfront in cash is necessary.
    The dream to make the money through salary and to go along will not work.
    45ft, have upfront $100,000. for the whole material and fittings
    Just an example.
  3. Pierre R
    Joined: May 2007
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    Location: ohio, USA

    Pierre R Senior Member

    Okay so we are still in a pissy rant. Fine

    I don't think at this point any of us are sure exactly what it is that you have decided to build. The last I knew you were going to build around a 40' cut down version of a 45 footer but were unsure how to re do the scantlings to match or what would happen to stability. Is that still the case or do have you settled on a build?

    You have given steel quotes of $15k to $20k and have a diesel engine and drive system.

    Let's assume your shop is free but your consumables and electricity are not. Consumables (weld rod, grinding wheels, air, gas, sand paper etc) will easily run $2k in three years. Electric probably a $100 a month so 36 months or eh about $3,600 in utilities. We assume you are heating with wood and that costs about $20 per face cord to cut so add about $1000.00 there.

    Window for the thing are probably going to run $50 a piece for the glass and you are going to scrounge and manufacture just about every thing else.

    You will have at least another $2k in minimum electrical and engine hookup stuff. Paint and blasting will run about $7k minimun so let's see. That could be done for $32k to get to a motor away unfinished condition. That is, a bare hull, painted with the running gear, fuel tanks, steering, windows, doors and minimum lights and battery system installed.
    No interior or systems installed and no commissioning work.

    If you go will bare minimums and end up with a house trailer/RV grade interior and systems you will add probably another $10-$15k. Commissioning with run a few thousand if you collect most of the items over the years. When you are done the boat would have been worth more had you stopped at the motor away unfinished stage. You might get your money out of it then. So under $50k and 4 years of work.

    Now of course this is only a guess and your costs will no doubt exceed all early estimates by at least 25%. That is if you have actually done this a few times already.

    Good luck, its a lot of money to gamble with for the average person and suitable used boats are cheaper.
  4. pdwiley
    Joined: Jun 2008
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    Location: Hobart

    pdwiley Senior Member

    Funny, for a sailboat just under 12m using 4mm plate for the hull and very extensive scrounging, my build budget is $40K AUD and I've allowed a 20% overrun contingency. If I can bring it in at that cost I'll be way under what people have told ME.

    You're going to build a 15m heavy displacement tug for half of my budget?

    Look, we know you can't afford to build it out of steel because you've said so.

  5. tugboat

    tugboat Previous Member

    wasnt referring to you specifically Richard..not necesarily at least...
  6. tugboat

    tugboat Previous Member

    i never said i couldn't i said i couldn't afford to build it out of steel -nested and cut and plate triples the costs...and also my post #1 was a few years ago...things have changed and


    steel has gone down in price here since post #1...
    also--i only recently costed it...

    note all sheets in 4x8 ft.
    heres the break down: steel-

    plating- 29 sheets 1/4 inch @ 170.00 ea. 4930.00
    frames: 33@ 3/8th $40 per 20ft length- need about 660 lin ft-$1320.00
    bulkheads: 4 @ 170.00 ea- 680.00
    there are no longitudinals.
    gussets- 2 sheets 1/4 inch -340.00
    keel, -1 inch by 5 inch- 600.00 (60 lin ft.)
    stem- (see keel)
    horn beam(3 inch x 1 inch) 30 lin ft- 300.00
    rudder- 1/2 inch stock sheet - 1 sheet @ 400.00 (aprox)
    misc steel i.e. bulwarks- caps- engine beds- floors, (im using non -integral tanks on the cheap)no tanks needed. 3000.00
    bitts . 400.00
    wheelhouse- (rememeber this is not a large wheelhouse)
    about 2500.00
    steering is cable drum type...i dont need sails like you do...or masts etc...

    misc steel not mentioned about 2000.00
    so far thats being generous too!

    engine and trans--own it
    prop- 400.00 but own one now...(and btw its also steel so no electrolysis)
    shaft(not using stainless) normal bar stock and dont tell me stainless is stronger its not I checked that out too!! it sjust rustproof...and my vessel is in fesh water
    shaft- 200.00
    decking - 3/16th at 300 squ ft- 9 sheets needed @ 138.00 ea. 1242.00
    misc 200.00 i.e. dorrs window etc..(plexigalss and wooden sliding door..not steel)

    subtotal- 18512.00

    thats the bare bones hull- engine installed- wheelhouse on, floors deck, prop, steering-launch ready.
    of course theres some misc items not mentioned but even if i add a generous 5000.00 more i think id still be under budget --im not using fancy commercial items... etc etc its all bare bones, and anything i dont need i wont use...

    so figure 5000.00 more for things i need on top of that -so thats about 24 512.00 roughly...and ive been generous because there are things i can do to skimp--id say its doable--but your entitled to your opinion...
  7. tugboat

    tugboat Previous Member

    yes i did forget to add in blasting of the hull sorry...i did abandon the 45 ft design in steel...i decided to go with fer-a-lite as a comprimise. its about half the costs of steel easily...there is much controversy with it..but ive done some research...But if i wanted to take more time --i could do the tug in steel...even if your figs are correct--it would still be a four year build. thats still less time than others ive seen...
  8. Pierre R
    Joined: May 2007
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    Pierre R Senior Member

    Tugboat you still have not adequately addressed your own worth. Having a hull cut from steel by NC cutting on a decent design could cut the hours needed by you for assembly to under a 1000 hours for the hull and you would have a fair hull that was worth what you put into it plus some real value for your time.

    What you are proposing is likely to be closer to 4500-5000 hours. When you are done the hull is not likely to be as fair and the boat will be worth next to nothing. Certainly less than what you have into it even if its less than half the price of the steel hull. Now if you went to Wally World and got a job and worked the difference of 3500-4000 hours you would have paid for the steel and the plans with far less hassle and have something to show for it.

    I used Wally World as this shows the true value of where you are placing your own labor at. With the worth of the boat when you are finished why do you even bother unless you do not count yourself as worthy at all.
  9. tugboat

    tugboat Previous Member

    Pierre R- O.k. possibly doing the frames may be cost beneficial..ill look into it...

    btw I am submitting those plans to an NA to have them rescaled to see if I could go to 40.5 ft again and 11.25 ft beam..everything would be rescaled down 10%...the reason is- not costs but size. one of the reasons I was going to abandon the project earlier was the boat is more boat than i need--and maybe i havent been clear on this either--but the reason i want o build is simply- I have not yet found a design i like as much as that one...if it can be rescaled by an NA, then its a much more practical for me--i.e. moving it and mooring etc..and perhaps becuase 45 ft is incredibly large. or to me seems to be...ive seen a similar sized 40 ft tug thats just about right...40 x 10ft Ville class...
    but no plans are available for it.

    tell me though-- I do have a lead on one. I went to see it. its in bad shape..needs sandblasting, needs to be replated in areas, and the wheelhouse is gone. need all refitting out- on the plus side--it has a shaft and prop, and steering gear. the guy wants 5000.00 for it-, im guessing its gonna costs double that to fix up and just about as much time to to do as a new hull..but do you think something like that is worth doing?
    in the end i still dont get the exact boat i like...however
  10. pdwiley
    Joined: Jun 2008
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    pdwiley Senior Member

    That budget looks reasonable except for blasting so 30 * 1.2 * 2.4 * 2 * 22 = $3800 roughly plus the flat bar, maybe another $500 plus odds & ends, call it $5000. Plus deck, I forgot to add it in.... 40 m2 so say another $800 - might all fit into $5000 depending on who does it etc.

    BTW your steel prices are very good, I wish I could get steel at that rate.

    I expect to spend $5000 on my blasting & priming and your hull is bigger so the figures don't add up to me. Close enough though, seriously a few thousand is 'noise' in a project this size (until you don't have it of course).

    I'll give you a minimum of $5000 to play with over me because of no rig, I forgot about that. I'm building a junk rigged schooner (unless I change my mind & rig it as a ketch) so my rig costs are a lot less than a marconi type rig. I also have a tight budget.

    You don't *need* a s/steel shaft and 316L is a ******* to machine too but as a matter of interest how much do you think you'll save? I can't do it as I'm in salt water and I only need 1.5m of 40mm shaft anyway so I wouldn't.

    I don't see paint anywhere in your budget. Add another $5000 to $7000 unless your paint prices are a lot better than mine. I'm using Jotun epoxy paints.

    You're missing a ton of stuff off of that list though. Anchors, rode, anchor winch, power systems, holding tank, head, insulation, dinghy, basic electronics (depth sounder & GPS), others can add to the list. It doesn't matter what you use for the hull material, this stuff costs money and adds up fast.

    I don't think you'll save money with non-integral tanks in a steel hull. This is an area where I haven't made up my own mind as yet. I built in keel tanks for fuel because it was waste space for anything else but water tanks etc, I may use polyethylene.

    If you have the money for a steel hull I honestly don't understand why you wouldn't build one instead of using a material with low to zero resale value that takes a lot longer as well, and is structurally weaker. If Tom Colvin says that FC takes 2X as long as other methods, please don't tell me that you can do better, and using Fer-A-Lite won't save you any time at all, in fact its sole advantage over cement is the ability to tolerate cold joints, implying that you can take LONGER to plaster the hull than if you were using cement.

    But it's your boat.

  11. Pierre R
    Joined: May 2007
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    Pierre R Senior Member

    Consulting an NA is very smart. You will get insurance easier and the boat will be worth more than the NA's fee will add. You also have someone to consult on construction.

    This type of plan is sound but I think you would do better to bide your time and find one in better condition for the same money. I would try Craigs list as Yachtworld is unlikely to list what you are looking for. There are several of these boats in the Great Lakes region that you might even be able to tow back home.

    Remember you will be blasting lead based paints so use a fresh air breathing system. If I were going to blast, I would rent a portable machine and blast with Garnet. Garnet cuts about 5 times faster than sand and does not loose its sharpness. A couple of days with a portable commercial unit with a closed breathing system and you are done.
  12. apex1

    apex1 Guest

    We used Copper Sack, when it was permitted. (still is in many areas)
    that is one third the cost of Garnet! And it is rather sharp and abrasive.

  13. tugboat

    tugboat Previous Member

    PDW--yes your right ferro is very labour intensive. And i did forget about blasting and painting..Are paints really that much???

    I think steel in North america might be lower, Im not familiar with your region (Australia?) and please forgive my lack of knowledge about it, but i believe if there isnt a lot of domestic production of steel it might be much mroe expensive...i think the steel distributer here said steel is aboput 68 cents a pound...but I priced on sheets of steel. they make 5 x 10 sheets too..but im sure you are aware of that--I tried to invrestigate cor-ten steel but its more rare here...they dont just stock it..its a special oreder and more costly...

    when i priced 2 inch bar stock for the shaft- the stainless was 1500.00!! the standard mild carbon steel was 200.00!! huge difference...It will have to be machined so i havent budgeted for that....what do you suppose the machining for the taper and thread would be in your area?..its probably similar here...
  14. tugboat

    tugboat Previous Member

    Pierre R I mentioned in my other thread--there is a 40 ft Russel tug which is very nicely designed. But its in extremely poor condtion. needs major blasting painiting and wheelhouse. Its rusted out bad..and needs replating too..i wonder if the costs of that would add up to what id build on for--the guy wants 5000.00 for it...seems expensive when ytou add up moving costs, blasting, painting replating etc and i cant be sure what the hull condition is...but i have thought about it and it could still be on the table...
    right now im ready to start my frames for this one...but i think i may wait a little bit until i get the info from the plans reduction.

  15. pdwiley
    Joined: Jun 2008
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    pdwiley Senior Member

    Yeah, paints aren't cheap. Not a great place to economise either though since you're in fresh water maybe you don't need to be quite so obsessive about the interior. Don't skimp on the exterior unless you like blasting back to bare metal (or FC/FAL) and starting over.

    We export megatonnes of iron ore, coal etc for steel making. Do you think steel is cheap here? Nooooooo........

    Generally you can get steel in a huge range of sizes but in practice your supplier carries what they carry. For a substantial order maybe they'd get the sizes you wanted. I'm using 3000 x 1800 sheets of 4mm and they're plenty big enough. I think 2400 x 1200 would have been better for me to work with actually.

    I wouldn't bother with Corten myself, in fact I didn't.

    You can probably do better on the s/steel by shopping around or asking a shop that runs a lot of stainless as their buy price will be better than yours. Regardless you're going to need the shaft machined on the inboard end to take a flange or other coupling to the gearbox and the outboard end for a taper or splines or whatever plus thread to mount your prop. I can't tell you the cost or even give you an estimate without knowing the coupling and prop mounting details. There are a number of shops that can do this sort of work and shop rate in North America/Canada seems to be in the $50-75 per hour range (I'm an active member of one of the machining forums). Shop guys make things to drawings so they know who to blame if it doesn't fit and fits need to have tolerances specified - eg if you want a coupling flange for a shaft that's 2" OD what's the tolerance on the shaft? Does the coupling need to be bored 2.000" plus a max of 0.002" minus 0.000" or what? What about the keyway? For jobs like this it's best to find a shop with the tooling and haul in all the bits so they can check the fits. If your prop has a taper fitting I wouldn't do it any other way myself as it's easy to be very slightly out on the taper.

    Mine won't cost me anything as I've got a machine shop with a lathe big enough to do the job. I'm also using taper-lock bushings and making my own flange using a Fenner taper-lock weldable flange blank. It works for big industrial drives, it's good enough for me.

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