Author Topic: Open Carriage Truck  (Read 1657 times)

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Offline Jon Nazareth

Open Carriage Truck
« on: Apr 01 2015 20:45 »
Good evening All,

What size bolt does the team think that 1863 W irons were fixed with?  14BA or 16BA? (you know what I mean)  The nut will show on the outside.

Regards
Jon

Offline blagdon

Re: Open Carriage Truck
« Reply #1 on: Apr 01 2015 23:01 »
Jon,

I should think they would have been a square nuts of about 1'' or so A/F; that relates to less than 1mm (I use principal of 1.125mm/inch for conversion. As for BA size, 16BA would be closest if you can; personally I prefer 14BA to holding solebar fixtures as with my 6/6 mono-vision that's the smallest I can cope with!

Ian the Gauge '3' Pirate

Offline MikeWilliams

Re: Open Carriage Truck
« Reply #2 on: Apr 01 2015 23:31 »
30 years after your date some at least were 1in Whitworth which I believe means 1.67in a/f.  However, before the War nuts were one size larger (reduced to save metal), so that would be 1.86in.  If my arithmetic is correct (always doubtful) that come to about 2mm in Gauge 3.

I find the size of BA nuts varies these days, so am not sure which is nearest - maybe 16BA?

Mike
 

Offline IanT

Re: Open Carriage Truck
« Reply #3 on: Apr 01 2015 23:50 »
I'd agree with Ian about the square head Jon.

Early railway stock seemed to owe quite a lot to the smithy practices associated with the (horse drawn) wagons of the day and they often used square bolts & nuts in their construction. The smallest screw fitting I've used in my models (thus far) has been 14BA but they are beginning to get expensive if you need a lot.

I've thought about making my own (square) nuts and I do have an article somewhere (by a modeller of agricultural wagons) on how he makes his scale nuts & bolts. Essentially, he drills a suitable 'tapping' hole in brass shim and then uses that hole to guide a punch & die set to punch out the actual nuts.

If you are interested, I could dig the article out and scan it for you. I guess you could also drill/part-off nuts from suitable square rod - but I suspect you might have to machine the rod square first, because I don't know if you can source square brass in the smaller sizes now. The punching method might well be both easier to do and easier to size correctly.

At 1" across, they would be 1.12mm scale (44thou) but I'm not sure about the size (and it's too late to go check!)

Regards

IanT
Nothing's ever Easy - At least the first time around.

Offline Andy B

Re: Open Carriage Truck
« Reply #4 on: Apr 02 2015 08:11 »
1" bolts are a bit on the big side for fixing axleguards.
An 1874 MR drawing shows 13/16" holes, i.e. 3/4" bolts. Hexagon nuts were being used at this date by some companies, whilst others continued to use square nuts 40 years later.
So I think only a photo or orignal drawing (of this or a similar wagon built by the same company) would provide a definitive answer.
Pre-war 3/4" W bolts used nuts of 1.3" A/F. (1.46mm or 0.057" in G3. 16BA are 0.054" A/F)

With my salesman's hat on. a reminder or another way of making nuts of correct dimensions is on this thread.

Andy

Offline MikeWilliams

Re: Open Carriage Truck
« Reply #5 on: Apr 02 2015 09:52 »
Thanks Andy, for pointing out that the table I used probably WAS the pre-War sizes, so I added one size in error.

Looks like 3/4in used by some railways, 1in used by others at a later period.  You may be safe with 7/8in!

Mike

Offline Jon Nazareth

Re: Open Carriage Truck
« Reply #6 on: Apr 02 2015 10:08 »
Good morning,

Thank you all for the responses.  I have looked at the drawing again, dated 1863, and it does show hexagon head nuts so, I'm guessing that would equate to 16BA with a washer as there is no crown plate.  I did make a nut spinner for 16BA and it holds just long enough to get a few turns on the bolt then it's fingers and tweezers to tighten it down.

Regards
Jon