Drilling handrail holes in boiler, how?

[bluestag]

Hey cats and kittens,

 

I am about to start work on a LNWR coal tank.    The boiler came rolled, but there are no indications of where the handrail holes go.    Any hints on how to mark them out?

 

Thanks

[Jeff Smith]

What type of kit is this?  Do you have a drawing showing handrail positions.  Is this the Webb coal tank, if so the hand rails run from smoke box right to the cab and parallel to the tops of the tanks.  It might be better to wait until the boiler and tanks are joined then measure from the tank tops.  I use a black indelible marker then a straight edge and scriber.  Once you have marked the positions use an adjustable automatic centre punch, preferably with some support inside the boiler.  Carefully drill with a pin-vice perpendicular to the surface.  Good luck!

 

Edited January 18, 2021 by Jeff Smith

[dpgibbons]

Masking tape will assist both marking out and drilling. 

[bluestag]

17 minutes ago, Jeff Smith said:

What type of kit is this?  Do you have a drawing showing handrail positions.  Is this the Webb coal tank, if so the hand rails run from smoke box right to the cab and parallel to the tops of the tanks.  It might be better to wait until the boiler and tanks are joined then measure from the tank tops.  I use a black indelible marker then a straight edge and scriber.  Once you have marked the positions use an adjustable automatic centre punch, preferably with some support inside the boiler.  Carefully drill with a pin-vice perpendicular to the surface.  Good luck!

 

Yes, it is the Webb coal tank, and I have the Talbot book on LNWR engines.    There is a weight diagram, useless, and a drawing that looks as if it was drawn for a hobby magazine.   It certainly was not drawn by Crewe.

 

I guess the concern that I have is to get the line level.   I don't think I'll use an automatic center punch.   The one I have would dent to boiler for sure.

26 minutes ago, dpgibbons said:

Masking tape will assist both marking out and drilling. 

Yes, masking tape to be sure.   It will keep the drill from skidding around.   But how to ensure a level run?

[Nick Holliday]

6 hours ago, bluestag said:

Yes, it is the Webb coal tank, and I have the Talbot book on LNWR engines.    There is a weight diagram, useless, and a drawing that looks as if it was drawn for a hobby magazine.   It certainly was not drawn by Crewe.

 

If you can get hold of "Bashers, Gadgets and Mourners" from the Bahamas Locomotive Society, you will find almost everything you need to know about Coal Tanks, including a general arrangement drawing, and a series of elevation drawings, at something like 5mm to the foot, showing typical conditions at various stages in their long life.

[micklner]

Use a Surface Gauge to create the straight lines.

[Brassey]

I also have 2 x 4mm Coal Tanks that need doing (old Jidenco). 

 

I have a LRM 4mm Coal Engine on the go and the instructions gives dimensions of the spacing between the handrail knobs and the height from the running plate.  IIRC it suggests marking the line in pencil.  I have done this already successfully on a LRM Special DX .

 

Unfortunately, I don't know if the Coal Tank uses exactly the same dimensions but if you need it I can send you the dimensions I have in 4mm and you can convert to 7mm.

[bluestag]

11 hours ago, micklner said:

Use a Surface Gauge to create the straight lines.

Don't have one.    Got some dividers, however.

[bluestag]

11 hours ago, Brassey said:

I also have 2 x 4mm Coal Tanks that need doing (old Jidenco). 

 

I have a LRM 4mm Coal Engine on the go and the instructions gives dimensions of the spacing between the handrail knobs and the height from the running plate.  IIRC it suggests marking the line in pencil.  I have done this already successfully on a LRM Special DX .

 

Unfortunately, I don't know if the Coal Tank uses exactly the same dimensions but if you need it I can send you the dimensions I have in 4mm and you can convert to 7mm.

So far the advice is to build it until there is a datum, ie the footplate or tanks.

[bluestag]

17 hours ago, Nick Holliday said:

If you can get hold of "Bashers, Gadgets and Mourners" from the Bahamas Locomotive Society, you will find almost everything you need to know about Coal Tanks, including a general arrangement drawing, and a series of elevation drawings, at something like 5mm to the foot, showing typical conditions at various stages in their long life.

THAT is an expensive read, if I want to buy one in the US.  From Britain would be worse.

[Brassey]

11 hours ago, bluestag said:

So far the advice is to build it until there is a datum, ie the footplate or tanks.

 

Yes like I said: "...height from the running plate."  (The LNWR called the footplate, running plate)

[Nick Holliday]

6 hours ago, bluestag said:

THAT is an expensive read, if I want to buy one in the US.  From Britain would be worse.

In the good old days of RMweb, you had to give a sensible location before you could post.  That seems to have gone by the board a long time ago, giving rise to unfortunate geographically inappropriate suggestions, like mine!

PM sent.

[bluestag]

24 minutes ago, Nick Holliday said:

In the good old days of RMweb, you had to give a sensible location before you could post.  That seems to have gone by the board a long time ago, giving rise to unfortunate geographically inappropriate suggestions, like mine!

PM sent.

Oh.   Well, I'm in Burbank CA

[ianLMS]

On the Right Track video, when building an Alan Gibson 4F, the infamous Mr Tony Wright uses a black marker pen run back and forth along the boiler, then I believe a waterline marker (used in model ship building) to run a straight line horizontally, marking only the marker pen.  He then marked along the line the spots where the handrail knob/split pin would go. A drawing is vital, or using photographs working out where they go in relation to other parts (chimneys, domes, lubricators etc) could be another approach. 

 

Worked for me, however, I only had digital calipers, not a waterline marker, but it did the same job. I used a sharp nail to make a small indent then as the boiler is quite thick I used my Proxxon drill to make the holes. 

 

I use split pins (the ones which come with markits/smiths coupling hooks) as my handrail clamps as I find the brass handrail knobs a little chunky.

 

Ian

[Jeff Smith]

Gibson handrail knobs are amongst the finest available for 4mm.  Three different lengths.

[ianLMS]

17 hours ago, Jeff Smith said:

Gibson handrail knobs are amongst the finest available for 4mm.  Three different lengths.

Totally agree. I use them for handrails on doorways, tenders etc. I only use split pins on boilers where you see on photographs the slimline type, thats almost just a strap.