Very old engines in Science Museum

Did I mention that I'd been to London's Science Museum?


Boulton & Watt, 1788. Sun and planet drive invented to avoid infringing William Pickard’s patent on the conventional crank. Seems incredible that the crank was patentable, but those lawyers got everywhere, even then.


Boulton & Watt, 1797. Worked until 1885.
Note early use of roller cam follower! Thought not to be original, but possibly dating from when engine was uprated in 1806……….


The cam operates rods and levers, and if there isn’t too much lost motion, it actuates the square-bodied valve (in photo above) to provide an early cut off of the steam and utilise its expansive properties. Note the plate-type spring above the valve. Immediately downstream of the cut-off valve is the throttle valve controlled by the flyball governor.



Beam engine built by Francis Thompson, 1791, for a colliery. The cast iron beam with the frivolous ornamentation was fitted later, when the engine was moved to another colliery.


From the Cubist School of engine design.


Triangular keys for an octagonal shaft.
Both the above photos were of a paddle steamer engine, I think.

There were a couple of model boilers that I wish I’d studied more closely:-


In this ‘Waggon’ type boiler, there’s no obvious way of knowing the water level, but there is a wooden float that opens a plug valve in the filler standpipe. Why, though, does the counterweight for the furnace damper live in the standpipe? It appears to made of lead, so it’s evidently not a float.


Lower pressure boiler, lower standpipe. The fire goes underneath and round the sides.
Chain on one end of the safety valve lever to allow it to be tested. Ample scope for putting extra weight on the other end drive the engine harder. This practice, together with bad design, poor workmanship, corrosion, low water level, etc., led to an early demise of many such boilers. How often did boilers blow up? Only once.

There’s an original version of one of these ‘haystack’ boilers on display with the 1791 beam engine, and also a nice old photo of one with a big opening in the side, with a horse emerging from it. Stable boiler conditions.

There’s an even older engine in the museum, a Watt beam engine dating from 1777, but it’s not much to look at. Originally an experimental engine nicknamed Beelzebub, it was tamed to pump water, and acquired the name Old Bess. The water was discharged to ….. the top of a water wheel. I don’t think that this was a means of avoiding the crank/flywheel problem, it just reflected fairly common practice for obtaining rotary motion.

Some of the engines had electric motors, but none of them were moving. Fortunately, if I want to see old engines running, in steam, I don’t have to travel far to the 1812 Crofton pumping engines.

Did I mention that I'd been to London's Science Museum?


Boulton & Watt, 1788. Sun and planet drive invented to avoid infringing William Pickard’s patent on the conventional crank. Seems incredible that the crank was patentable, but those lawyers got everywhere, even then.


Boulton & Watt, 1797. Worked until 1885.
Note early use of roller cam follower! Thought not to be original, but possibly dating from when engine was uprated in 1806……….


The cam operates rods and levers, and if there isn’t too much lost motion, it actuates the square-bodied valve (in photo above) to provide an early cut off of the steam and utilise its expansive properties. Note the plate-type spring above the valve. Immediately downstream of the cut-off valve is the throttle valve controlled by the flyball governor.



Beam engine built by Francis Thompson, 1791, for a colliery. The cast iron beam with the frivolous ornamentation was fitted later, when the engine was moved to another colliery.


From the Cubist School of engine design.


Triangular keys for an octagonal shaft.
Both the above photos were of a paddle steamer engine, I think.

There were a couple of model boilers that I wish I’d studied more closely:-


In this ‘Waggon’ type boiler, there’s no obvious way of knowing the water level, but there is a wooden float that opens a plug valve in the filler standpipe. Why, though, does the counterweight for the furnace damper live in the standpipe? It appears to made of lead, so it’s evidently not a float.


Lower pressure boiler, lower standpipe. The fire goes underneath and round the sides.
Chain on one end of the safety valve lever to allow it to be tested. Ample scope for putting extra weight on the other end drive the engine harder. This practice, together with bad design, poor workmanship, corrosion, low water level, etc., led to an early demise of many such boilers. How often did boilers blow up? Only once.

There’s an original version of one of these ‘haystack’ boilers on display with the 1791 beam engine, and also a nice old photo of one with a big opening in the side, with a horse emerging from it. Stable boiler conditions.

There’s an even older engine in the museum, a Watt beam engine dating from 1777, but it’s not much to look at. Originally an experimental engine nicknamed Beelzebub, it was tamed to pump water, and acquired the name Old Bess. The water was discharged to ….. the top of a water wheel. I don’t think that this was a means of avoiding the crank/flywheel problem, it just reflected fairly common practice for obtaining rotary motion.

Some of the engines had electric motors, but none of them were moving. Fortunately, if I want to see old engines running, in steam, I don’t have to travel far to the 1812 Crofton pumping engines.

Asquith,

Thanks for the iinteresting photos.

If you want to go a bit further afield, you can see a genuine Boulton and Watt sun and planet engine running under steam at:
http://www.powerhousemuseum.com/opac/18432.asp
Might be a bit far for a weekend jaunt though.

Somewhere I have an engraving of a waggon boiler reproduced from an 1860s book. From memory this shows the water level indicator to be just a float inside the boiler attached to a rope running over a pulley with a weight on the other end with a pointer attached which can be read against a scale. Don't know if there is some artistic licence in this, but there is no obvious means visible in the engraving of sealing against steam leakage where the rope exits the boiler. Maybe at the pressure these operated the amount of steam loss would be negligible? It is some time since I saw the Bolton and Watt engine running, but if my rather fallible memory is correct, the steam pressure gauge was reading about 4 psi at the time.

franco

Asquith,

Thanks for the iinteresting photos.

If you want to go a bit further afield, you can see a genuine Boulton and Watt sun and planet engine running under steam at:
http://www.powerhousemuseum.com/opac/18432.asp
Might be a bit far for a weekend jaunt though.

Somewhere I have an engraving of a waggon boiler reproduced from an 1860s book. From memory this shows the water level indicator to be just a float inside the boiler attached to a rope running over a pulley with a weight on the other end with a pointer attached which can be read against a scale. Don't know if there is some artistic licence in this, but there is no obvious means visible in the engraving of sealing against steam leakage where the rope exits the boiler. Maybe at the pressure these operated the amount of steam loss would be negligible? It is some time since I saw the Bolton and Watt engine running, but if my rather fallible memory is correct, the steam pressure gauge was reading about 4 psi at the time.

franco

On my first visit to the Powerhouse Museum in Sydney I was in one section when I heard a lot of thumping, hissing and other unusual noises from another part of the building.

Upon investigating I found the section where the Boulton & Watt engine and several other steam engines are kept.

Many were running; the experience was wonderful

It transpired that most of the engines were run once-a-week at a certain time; 11am on Thursdays rings a vague bell but it WAS many years ago.

The sight/sound/smell of several engines, large and small, all running in the one hall is not to be missed; I'm glad that Providence took me to that place on that day & time.

On my first visit to the Powerhouse Museum in Sydney I was in one section when I heard a lot of thumping, hissing and other unusual noises from another part of the building.

Upon investigating I found the section where the Boulton & Watt engine and several other steam engines are kept.

Many were running; the experience was wonderful

It transpired that most of the engines were run once-a-week at a certain time; 11am on Thursdays rings a vague bell but it WAS many years ago.

The sight/sound/smell of several engines, large and small, all running in the one hall is not to be missed; I'm glad that Providence took me to that place on that day & time.

Thanks very much for the pictures.

The sun and planet picture . . . I wonder if the flanged sun gear was a fix for overloaded teeth? . . . or another purpose? The original Watt patent shows a conventional spur gear. Were these gears used as cast, or hand finished?

Thanks very much for the pictures.

The sun and planet picture . . . I wonder if the flanged sun gear was a fix for overloaded teeth? . . . or another purpose? The original Watt patent shows a conventional spur gear. Were these gears used as cast, or hand finished?

One of the interesting features of the sun and planet crankshaft connection is that the flywheel rotates faster than the connecting rod.

I was in the Science Museum one day and happened to ask one of the white-coated men who were running the big mill engine if they ever ran the older engines. He took me over to one of them (I can't remember which one) and started it up for me - electrically driven, that is. The flywheel speed was quite obvious, but the chap who ran it hadn't noticed before and I had never seen one running, so we both learnt something.

It sure would be nice to see the B&W engine in Sydney running on steam, it is on my list of places to visit one day.

Hunter,
Might be hard to see the original finish now after 88 years service But I am sure it wouldn't have phased a B&W workman to get in there and chisel out anything he didn't like

One of the interesting features of the sun and planet crankshaft connection is that the flywheel rotates faster than the connecting rod.

I was in the Science Museum one day and happened to ask one of the white-coated men who were running the big mill engine if they ever ran the older engines. He took me over to one of them (I can't remember which one) and started it up for me - electrically driven, that is. The flywheel speed was quite obvious, but the chap who ran it hadn't noticed before and I had never seen one running, so we both learnt something.

It sure would be nice to see the B&W engine in Sydney running on steam, it is on my list of places to visit one day.

Hunter,
Might be hard to see the original finish now after 88 years service But I am sure it wouldn't have phased a B&W workman to get in there and chisel out anything he didn't like

Peter,
There’s clearly more to the sun and planet crank than meets the eye. Shall I get my pencil and compasses going, or find some gears and play? Neither of the above, I’ll do some work.

I wonder how often the gears disengaged during operation?

Hunter,
I normally regard the flanges as a means of adding strength to cast gears, but in the case of the beam engine in the photo, the flanges may have been there to keep the con rod gear from straying sideways. Here’s another variation, which seems odd at first sight, but then I realised that it would encourage smooth running and prevent the gears over-engaging:-
1797 Engine

I don’t think cast gears would have had much finishing beyond filing the ‘nibs’ off, especially with shrouded gears with restricted access to the flanks. I was impressed by the finish on a cast gear on the 1817 Richard Roberts lathe in the museum. This photo doesn’t do it justice:-
Gear

Peter,
There’s clearly more to the sun and planet crank than meets the eye. Shall I get my pencil and compasses going, or find some gears and play? Neither of the above, I’ll do some work.

I wonder how often the gears disengaged during operation?

Hunter,
I normally regard the flanges as a means of adding strength to cast gears, but in the case of the beam engine in the photo, the flanges may have been there to keep the con rod gear from straying sideways. Here’s another variation, which seems odd at first sight, but then I realised that it would encourage smooth running and prevent the gears over-engaging:-
1797 Engine

I don’t think cast gears would have had much finishing beyond filing the ‘nibs’ off, especially with shrouded gears with restricted access to the flanks. I was impressed by the finish on a cast gear on the 1817 Richard Roberts lathe in the museum. This photo doesn’t do it justice:-
Gear

Asquith:

Delightful pictures of some really interesting
engines. The workmanship, considering the equip-
ment available at the time, is really first class.
These ingenious machines helped make our present
standard of living possible. The oldest engine of
this type that I have had any experience with, was
built in 1811 by James Watt and Company, Birming-
ham. It was located in a Dublin distillery, oper-
ating at 35 RPM, it drove the machinery for grind-
ing the grains and, I believe, the mash tuns.

Hendeyman

Asquith:

Delightful pictures of some really interesting
engines. The workmanship, considering the equip-
ment available at the time, is really first class.
These ingenious machines helped make our present
standard of living possible. The oldest engine of
this type that I have had any experience with, was
built in 1811 by James Watt and Company, Birming-
ham. It was located in a Dublin distillery, oper-
ating at 35 RPM, it drove the machinery for grind-
ing the grains and, I believe, the mash tuns.

Hendeyman

Splendid stuff Asquith...once again you make me wish that I was older than I am

regards

Brian

Splendid stuff Asquith...once again you make me wish that I was older than I am

regards

Brian

Asquith, Peter . . . thanks for replies

Thought an image of the Watt patent might be fun:



Of course, this is a patent drawing so probably wouldn't have shown the flange detail unless a patentable feature . . . or, simply a later feature.

Do you think the flanges in the 1797 Engine photo acted as bearings or just guards to hold pitch diameter? Isn't it difficult to have it both ways?

In the lathe gear photo, the as cast finish is lovely. The 11 O'Clock tooth of the shrouded gear does seem to have been loafing a bit. Is the next tooth (CCW) a significantly different form, or just the photo angle?

Asquith, Peter . . . thanks for replies

Thought an image of the Watt patent might be fun:



Of course, this is a patent drawing so probably wouldn't have shown the flange detail unless a patentable feature . . . or, simply a later feature.

Do you think the flanges in the 1797 Engine photo acted as bearings or just guards to hold pitch diameter? Isn't it difficult to have it both ways?

In the lathe gear photo, the as cast finish is lovely. The 11 O'Clock tooth of the shrouded gear does seem to have been loafing a bit. Is the next tooth (CCW) a significantly different form, or just the photo angle?

I have long been troubled by the sun and planet thing - what holds it altogether?

I have assumed that there must be a link between the two gears, keeping their centre-distances tied.

Hunter, thanks for the patent drawing, it shows a link option, as the Science Museum doesn't seem to be using the "wheel GG and its groove".

I have thought up to now there must be a link on the flywheel side of the gears, unseen in the photos?? Is this correct, or is there something else going on here?

Also, I have to confess to be ignorant of how the gear ratio works between the gears, can anyone explain what the ratio would be - say with two gears with the same number of teeth?

I have long been troubled by the sun and planet thing - what holds it altogether?

I have assumed that there must be a link between the two gears, keeping their centre-distances tied.

Hunter, thanks for the patent drawing, it shows a link option, as the Science Museum doesn't seem to be using the "wheel GG and its groove".

I have thought up to now there must be a link on the flywheel side of the gears, unseen in the photos?? Is this correct, or is there something else going on here?

Also, I have to confess to be ignorant of how the gear ratio works between the gears, can anyone explain what the ratio would be - say with two gears with the same number of teeth?