Vic Smeed’s Silver Mist

[Tony HadleyParticipant @tonyhadley]

A photograph of Vic Smeed with his Silver Mist from the 1966 edition of the book Power Model Boats.

[Bob Abell 2Participant @bobabell2]

Looks nice, Tony

He certainly was a prolific builder………Mdel aircraft too

Bob

[Ian GardnerParticipant @iangardner62867]

Bob,

Going back to your question about weight, the 14 or 15lb (can't quite remember which) I mentioned would be the all up sailing weight to ballast it down the the designed waterline. I can't remember what weight of ballast went into the boat but I could check as I only tack lead weight into my boats.There is no doubt at all that your boat will require a high proportion of ballast weight and of course, the bigger the scale, the higher proportion of ballast will be required unless you are planning a ferro-cement hull!

Tony,

I pored over that picture for years before building Silver Mist- I always like the design of the motor cruisers in the foreground too.

[Bob Abell 2Participant @bobabell2]

Hello Kevin

Am I missing something here?

I have just measured up my Pocahontas Marbleclass yacht

It is 4`- 2" overall length x 10" wide and about the same depth of hull as Silver Mist

It is fully ballasted and weighs 20lb

I have been advised by PM, that I should expect an all up weight of 40 to 50 lb for a 4` – 0" hull

I think the weight will end up at 25lb

It will probably float high in the water and look silly

Got a very sneaky solution!…………And is probably the answer to a Maidens Prayer?

Bob…….Getting on a bit now

[Ian GardnerParticipant @iangardner62867]

Hi Bob,

There are four foot hulls and four foot hulls. A 4'x10'' tanker will weigh more than a 4'x10'' steam yacht as they have different block coefficients, ie the tanker will represent much more of the rectangular block measuring 4' x 10'' than the steam yacht, the latter being much finer lined.

I don't think your Silver Mist will be anyting like 40 or 50lb. I shouldn't get too hung up on the final weight. I just wanted you to know that it will be quite heavy and will require a fair amount of ballast. The Silver Mist hull isn't as burdensome the same sized tug might be, which could well weigh 40lb. There's no real way round it- it must float to its designed waterline or, as you say, it will look silly. Removeable ballast or water ballast tanks may be a way to go- but it won't be that heavy. The other alternative is to go back to 42''- still a good size.

The nice thing about heavy models as you know, is the way they sit on and move through the water. I think your Silver Mist at 48'' will be brilliant and I can't wait to see how you get on with it.

Have fun and all the best,

Ian

Edited By Ian Gardner on 01/04/2016 13:51:42

[IAN_IParticipant @ian_i]

Hi Bob.
look forward to following your new build.
best regards
Ian

[Bob Abell 2Participant @bobabell2]

Thank you, Ian

You are very welcome

BTW………Not got the plan yet

Bob

[Colin BishopModerator @colinbishop34627]

Bob,

The plans are printed to order by an external company.

Colin

[Paul TParticipant @pault84577]

Captain Bob

Re your notion about avoiding ballast, if its what I think it is I did the same thing on a six foot TID and whilst it solved the ballast problem it created another with the hull rolling.

Paul

[Colin BishopModerator @colinbishop34627]

No wheels on this one Bob, no wheels….

Colin

[Bob Abell 2Participant @bobabell2]

Don`t forget, Colin…….The wheels was your idea!

And it turned out well!

Bob

[Colin BishopModerator @colinbishop34627]

Quite true Bob, I think that is what they call serendipity!

Colin

[Bob Abell 2Participant @bobabell2]

Paul and I are on the same wave length and he has twigged the gist of my ballast solving solution?

In fact, I'm using no ballast at all…..Hence, the answer to a Maiden's prayer!

The hull bottom is open to the pond water, but the hull has a dummy watertight bottom at the design waterline

The motor and gear will be housed above the floor and the propshaft will protrude through the the floor and down to the stern

There will be a possible air pocket Above the waterline, but this will be solved by breathing holes on the waterline, or an air release tap in the chimney…….As Paul did on his tug boat and achieved a satisfactory solution

Now looking forward to the four foot build…..Which will be quite light and I guess about 15lb?

Bob

[Paul TParticipant @pault84577]

Captain Bob

Even though you have provided a brief outline of your plans some people might not understand the principal of free flooding hulls.

It would help Kevin immensely if you posted a couple of sketches showing how the system works.

Paul

[Bob Abell 2Participant @bobabell2]

Hello Paul

That's a good idea………But first……

Looking at the mini drawing, the waterline depth is 3" and if my maths are correct, the displacement weighs in at 29lb

The hull would have had about 20lb of lead plus 10 lb of gear and 15 lb max for the model

As built, the all up weight would have been about 45 lb

With the water filled hull idea, the dry weight is now 25 lb…………Any comments?

Just for interest, I'll see what Brutus weighs

Bob

[Phil H1Participant @philh196021]

Paul/ Bob, I think I understand roughly what you are trying to do with the false hull but yes a simple toy boat type sketch would be great.

You more experienced guys are discussing various weights. At what point does the boat get a bit tricky to handle. For example, what is wrong with 45lbs? Less than an old bag of spuds? Is it just really tricky to load the boat in and out of the water?

PhilH

[Colin BishopModerator @colinbishop34627]

Phil,

It's not just the weight of the boat – it's the age and knee condition of the boater as well!

Colin

[Bob Abell 2Participant @bobabell2]

Hello Phil

You are quite right……45 lb is no big deal, like you say, but to an old geezer like myself at 79 years, it's not very comfortable, launching such a weight as Colin is also aware of!……Ho! Ho!

The novelty of having a water filled hull section is interesting to mess with and could be handy for really large models

Thanks for posting

Bob

[Paul TParticipant @pault84577]

Bob

If you enlarge your mini drawing to a point where the hull measures 1200mm (4ft) you will find that draft is 150mm (6in) this increase in size gives you a whole new set of measurements from which you can recalculate your results.

The dry weight of Brutus has no comparisons with the Silver Mist as Brutus was designed to sit on top of the water.

Phil

Good point and as Admiral Colin points out its usually down to the person doing the lifting rather than the weight of the boat. To use your bag of spuds analogy try holding the bag at arms length and lowering it 3 to 4 ft and then lift it back up the same way.

Trimming a large model boat usually has to be done after launching as, unless you have a launching trolley and slipway, the overall weight of the boat could cause you to loose balance and enter you into an unexpected comical diving competition. Even the strongest have been surprised by the waters suction effect on a heavy boat when lifting it out of the water.

The principal will become clearer when Bob posts his technical drawings.

Paul

[Bob Abell 2Participant @bobabell2]

Paul, old son, when I've glued in the false waterline floor and let the water in the lower hull…….

I'm left with a Brutus and the same length too……Because it sits on the water

Bob

[Paul TParticipant @pault84577]

Bob

I think I understand what you are driving at but the comparison is still tenuous as the above waterline mass is different, Brutus was designed to be a lightweight boat whereas Silver Mist had no such restrictions.

There is a chance that Kevin is becoming confused with these references to Brutus especially as Brutus doesn't have a free flooding hull.

Your drawings will help make things a lot clearer.

Paul

[Bob Abell 2Participant @bobabell2]

Hello Paul

Have tried to use the reduced plan as a starting point

Have noticed on a previous post, that you mention a 6" draft………I get a 3" draft for some reason?

If we have holes in the lower hull section, close to the water line, there will be no need for an air valve

Looking forward to see how the idea works out and if it is an answer to a maidens prayer?

Bob

[Ray Wood 3Participant @raywood3]

Hi All

Here is my winter project a 30" version of Vic's classic Silver Mist only ballast needed is 2nr x 6 cell sub C battery packs and 1/2 lb of lead in the bows too achieve the scale waterline. Balsa 3/16" planked and West epoxy resin inside and out.

[Paul TParticipant @pault84577]

Bob

The design office has sent you an internal memo regarding your drawing.

[Bob Abell 2Participant @bobabell2]

Hello Ray

Your model looks very nice…….Where have you got access to the gear inside, please

We are surprised that you have only got 1/2 lb of lead for ballast for a 30" model?

Paul

Thanks for the PM and comments

As already mentioned, the plan has arrived and can now make a start on the construction

Think we need another rethink on the ballast situation?

Bob

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