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boiler sizes

Posted by bill 
boiler sizes
August 24, 2010 07:16PM
Stanley boiler sizes 20 hp 23'' boiler measures 24.5'' od. 30 hp 26''boiler measures, 27.5'' od. .250 shell, .375 bands. I think it's right. How many tubes are they supposed to have ?
Re: boiler sizes
August 26, 2010 11:30AM
It all depends who built the boiler or is building one.

I have what I believe is an original Stanley boiler 23 inch with a LIGIMENT spacing that average’s 0.189 near 750 tubes. What is more common is a LIGIMENT spacing of 0.3125 with 592 tubes.

I have seen 14 inch boilers with LIGIMENT spacing of 0.2088 with 299 tubs as well as only 250 tubes.

18 inch boilers with LIGIMENT spacing of 0.3125 and 340 tubes.
I built mine with 0.200 and have 491 tubes.

I have seen many old boilers not knowing of their originality with LIGIMENT spacing varying from as much as 0.5000 to as small as 0.189.

I hope this helps for an answer.
Re: boiler sizes
August 26, 2010 12:14PM
Tube sheet and shell thickness also vary,,,,The 30" racing boiler was alledged to have 1485 tubes,,,but the weight of that doesn't compute,,so now we add the factor of what dimentions we can take for fact,, I wish they had saved the boiler along with the engine and axle,,,Ben
Re: boiler sizes
August 26, 2010 01:27PM
Dear Ben, What weight did they say that the 30" racing boiler weighed? What weight does the 30 hp racing boiler pencil out to weigh?
Re: boiler sizes
August 27, 2010 09:37AM
The ASME guides discuss ligament spacing.

Karl Petersen
Re: boiler sizes
August 27, 2010 03:25PM
ligament spacing
I think you will find the general requirements in the ASME code in Section 1 PG-52.1
and calculation section V111 Div 1
Re: boiler sizes
August 27, 2010 04:24PM

According to Drawing set 13 from Light Steam Power, which is of the Rocket Engine, the boiler had 1,478 copper tubes 33/64" od 20 gauge. 30" diameter and 18" high, 285 sq ft surface area and 512 lbs. I don't know if the weight includes the burner or not, it also states that the burner ran at 160 psi. The engine weight is stated at 205 lbs.

Caleb Ramsby
Re: boiler sizes
August 28, 2010 01:36AM
If you figure the ligament and minimum spacing to the shell are both .18", I just laid out 1587 33/64" dia tubes in a 29.64" circle.

So what is the spacing or ligament which was shown on Drawing Set 13?

Karl Petersen

Edited 1 time(s). Last edit at 08/28/2010 01:41AM by Karl Petersen.
Re: boiler sizes
August 28, 2010 07:55AM
Kit Foster’s book
Page 217 in 1907 they jacked the pressure to 1300 PSI and ran fuel (Page 219) pressure at 200 PSI.

Original Stanley literature says the 30 HP type 4 engine Wt was 254 Lb.

All the other stuff you posted is the same. Tube count ect.
The fuel pressure of 160 most likely was 1906 record.

I also did a tube layout for the 30-inch boiler. The first time I did it as a typical Stanley layout and got 1487 tubes, not 1478. Then I remembered reading somewhere that on the racer boiler steam was drawn off from three locations. Second layout I got 1479. Unless I miss counted.

Re: boiler sizes
August 28, 2010 11:51AM

Ironically drawing set 13 is a single piece of paper. It has undimensioned 1/3 scale drawings of the engine and dimensioned full scale drawings of part of the cylinder block and valve and ports. No drawings of the boiler, burner, pumps, axle or anything else.

The data I quoted was described as being from Fred Marriott.

Rolly/CAD Wizard,

I wonder if the prototype 4 1/2" by 6 1/2" they used on the Rocket was a bit lighter or Freds memory could have been off.

I didn't know about the tiple steam outlets, makes complete sense, they would be able to carry the water higher without local priming. Have you heard of anyone using multiple steam outlets on thier road going Stanley?

I also wonder if they changed the size of the venturis and nozzles along with the fuel pressure for 1907. Neat stuff.

In regards to tube spacing.

Here is a formula from the Machinery's Handbook that determines how many inscribed circles can fit within a circle.

N= number of inscribed circles
R= Ratio = large circle / small circle
D= large circle diameter
d= small circle diameter

N= 0.907*(((D/d)-0.94)*((D/d)-0.94))+3.7
R= 0.94+ sqrt((N-3.7)/0.907)

Using 1,478 to find R we get, 41.257. Dividing 30" by 41.257 we get .727", subtracting .515(33/64"winking smiley we get .212". So that would be the min tube wall to tube wall gap according to that formula.

If instead we use 47/64" for the inscribed circle, which is .7343 and use the same ratio found above, then we get a large circle of 30.29"
With 23/32", which is .7187" we get a large circle of 29.65". These would have a tube to tube min gap of respectively .219" and .204".

For 45/64"(.7031"winking smiley we get a large circle of 29" and a min gap of .1881". That sounds pretty tight, but it was a racer, it would also give the geatest clearance between the od of the outside tubes and the inside of the shell. It is also within what Rolly has found.

Caleb Ramsby
Re: boiler sizes
August 28, 2010 12:34PM
I noticed in the photos of the wrack in 1907 there was no indication of the copper cylinder lagging around the engine or rear end housing. It is told they swapped out the engine with one that was in the Vanderbilt just before the race of the wrack. Not a lot of wt there. The early frame 30 HP engine is kind of skimpy from the one’s I’ve seen.
They started using the 30 HP engine in 1908 in the model K-M-and Z same frame rod spacing as the 20 HP engine 5-3/4, but with 7/8 bolts.

The 30 HP of 1910 was heaver with 6-3/4 bolt spacing and one inch frame rods. Then in 1915 they went to 1-1/8 rods. Same spacing.

Kit Foster book page 219 story by Marriott told by Tom Marshall, the burner had four nozzles and mixing tubes carrying 200 PSI fuel pressure.

Re: boiler sizes
August 28, 2010 03:27PM

Those are some keen observations. I wonder if they also changed the crosshead and connecting rod lengths, as well as frame lengths when they beefed up the frame rods for the heavier engine. There is also the detail of the wall thickness of the various parts of the block. The drawing set 13 shows 7/8" rods on a 5 3/4" spacing. Cylinder wall thickness of 11/32", the rest of the walls are between 9/16" and 5/16".

The only gearing reported in the drawing set is 82 teeth on the engine and 48 on the differential.

Does anyone know if they used ferrules on the Rockets boiler, or when they began to use them or was that more of an aftermarket thing? It seems to me that the ferrules would have a lot to do with the min tube spacing.

Caleb Ramsby
Re: boiler sizes
August 28, 2010 06:06PM
The type 4 engine is very light,,,the block weighs in at #50,,the #8 is 75 I think,,,Wt difference of 06-07 ,,Part of the wt COULD be difference of gears,,Did they weigh it both times w/the axle brackets??,,Has someone used 1910 weights??,,,,I think the 07 boiler had steel tubes,,,does anyone know if they used cupernickel [trade'mk ] at this time,,,The 06 and 07 engines were geard very different,,,,the 07 turning faster if I recall,,,The big boiler tends to prime,,I have 3 outlets on the racer,,but in long cutoff that engine will pass a suprising volume of water,,,Oh yes the b/s is the same,,,but,,,the cylender covers have a different thread,,,,12--14 tpi,,,dont assume ////,,, Careful reading will show they broke more engines than I thought they had made,,, What happend to those other engines,,,Fred told me that the racer got light to HANDLE when the throttle was opend,,,light steering,,!!!,, haha,,, in haste,,Ben
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File Name File Size   Posted by Date  
30 inch boiler-1479.jpg 154 KB open | download Rolly 08/28/2010 Read message
30 inch boiler 1487.jpg 176.8 KB open | download Rolly 08/28/2010 Read message
Boiler section.JPG 82.9 KB open | download Rolly 08/28/2010 Read message
Drawing2.jpg 46.6 KB open | download Rolly 08/28/2010 Read message