TID steam tug 42″ – PN Thomas drawing enlarged

[Ray Wood 3Participant @raywood3]

Thanks Guys,

Well I was born with a sheet of 1/16″ plywood in my hand, 🙂 I blame my dad for having all the tools and materials to learn to make things !! he also taught me to scale up drawings when I was about 8 years old !!

The weight of the is still going to be a mystery ! once I have sealed the hull I will find how much ballast it will need, watch this space, the ships wheel just arrived from Cornwall model boats, I’m not painting her till after the Southern Model Show on the 30th & 31st August the tug will be on the Cygnets stand on Saturday and the Chantry stand on Sunday 🙂

It’s probably the biggest show of model boat clubs of the year down South here in Kent and with RC flying , cars & trains something for everybody 🙂

Regards Ray

[Colin BishopModerator @colinbishop34627]

The weight of the is still going to be a mystery !

Not necessarily if you have built a a scale model Ray. Extract from my 60th Anniversary Special Issue:

Scale Displacement

This sort of calculation can be even more impressive applied to scale models of larger craft, in smaller scales. A 4ft. long model of a Leander class frigate (2,200 tons displacement) for example, which would be 1/100th scale. True weight for such a model would be 1/100 x 1/100 x 1/100 x 2200 tons or a mere 51b! If it was not, and the hull lines were true scale, it would not float at the same waterline.

I have done a rough calculation on a TID which you might like to check:

Model length 42 inches Original vessel 65 feet approx scale 1:18

Actual displacement  124 tons, Using the formula above model displacement about 47.5lb which seems about right.

Colin

 

[Ray Wood 3Participant @raywood3]

Thanks Colin,

That looks very scientific 🙂 I hope it doesn’t weigh that much !!

Time will tell I suppose, as its a chine hull I’m not expecting to be any where as heavy as my old Cullamix which I think was around 35 lbs all up .

Regards Ray

[Colin BishopModerator @colinbishop34627]

I made an error! The tug length is listed as 65 feet but that is between perpendiculars and the length overall is around 75 feet which makes the scale around 1:21!

So 124 long tons x 2240lb = 277760lb displacement. Divide by 21 three times and it comes out at about 30lb

I have done this on a couple of my boats in the past and the formula has worked surprisingly well.

What is a surprise is the exponential effect of using 1:21 scale instead of 1:18.

Colin

[Ray Wood 3Participant @raywood3]

Thanks Colin,

That’s a relief 🙂  I thought I’d be needing a trailer !!

Regards  Ray

[Anthony ShilsonParticipant @anthonyshilson68083]

I’ve just used Colin’s calculations for my tug project ~ 85lb…. Ouch and I hope my calculations are wrong 🙂 .

[Boiler BriParticipant @boilerbri]

Looking good Ray.

I think my next one is going to be a Remora. Just sketching out the frames.

 

Reagrds

 

Brian

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