Egg ended boiler


Frank Stamford
 

Hello all,

I have received the following request via the lrrsa's generic email address.

Can anyone help the enquirer?

Regards,

Frank

---------------------------------------------------

Date: 8/2/2010 22:06:51 +1100
From: Georgina Element <crella25@hotmail.com>
To: <lrrsa@lrrsa.org.au>
Subject: Egg ended boiler
________________________________________

Hi there,

I'm in Mt Kembla NSW, near Wollongong, where we have an egg ended boiler that came from the Mt Kembla Coal mine originally, but is now in a horse paddock. I was told by Graham Clegg from the Powerhouse Museum a couple of years ago, that you have conducted a lot of reserach into mines in Australia. I was wondering if you could point me in the right dirrection to find out more about this boiler: where it came from, how it was made and used...

It is made of three iron plates to achieve the diameter of the boiler. There are pictures of it on Fickr if you serach Mt Kembla Boiler. See link below:
http://www.flickr.com/search/?q=Mt+Kembla+Boiler

I've been searching on the internet for information on egg-ended boilers, but I have found out very little really.

Thank you for your time.

Kind regards,

Georgina Element


John Garaty
 

Hi Frank,
It looks more like an air receiver or airtank for the mine or some other associated plant. It looks like both ends are domed and there are no fireholes, flues or gauge glass fittings apparent in the photos.

Such a tank or tanks could be used as a "buffer" to enure that there was a sufficient supply of pressurised air for the operation of pneumatic drills etc underground at the end of airline from the surface.

There appears to be 2 similar elevated tanks in the foreground at Corrimal here:
<http://mylibrary.wollongong.nsw.gov.au/cgi-bin/spydus.exe/FULL/PIC/BIBENQ/4821076/10828326,9?FMT=IMG>

I bow to other mining/power enginneers and miners who may have knowledge of the operation of such equipment.
Regards,
John Garaty
Unanderra
Just down the road from Mt Kembla

--- In LRRSA@yahoogroups.com.au, "fstamford" <frank.stamford@...> wrote:


Hello all,

I have received the following request via the lrrsa's generic email address.

Can anyone help the enquirer?

Regards,

Frank

---------------------------------------------------

Date: 8/2/2010 22:06:51 +1100
From: Georgina Element <crella25@...>
To: <lrrsa@...>
Subject: Egg ended boiler
________________________________________

Hi there,

I'm in Mt Kembla NSW, near Wollongong, where we have an egg ended boiler that came from the Mt Kembla Coal mine originally, but is now in a horse paddock. I was told by Graham Clegg from the Powerhouse Museum a couple of years ago, that you have conducted a lot of reserach into mines in Australia. I was wondering if you could point me in the right dirrection to find out more about this boiler: where it came from, how it was made and used...

It is made of three iron plates to achieve the diameter of the boiler. There are pictures of it on Fickr if you serach Mt Kembla Boiler. See link below:
http://www.flickr.com/search/?q=Mt+Kembla+Boiler

I've been searching on the internet for information on egg-ended boilers, but I have found out very little really.

Thank you for your time.

Kind regards,

Georgina Element


Stephen Percy Larcombe
 

John, I think you are wrong. There is such a thing as an "egg ended boiler".



This boiler looks pretty much exactly like what they should look like.



The book "Historic Steam Boiler Explosions" by Alan McEwen has a write up on a bank of these boilers exploding at a blast furnace.



The boilers were described as 64 feet long, externally fired (hence no fire tubes or furnace tube(s)). They were fired on blast furnace gas. They ran at about 54 psi (if my memory is correct). Boiler number 5 failed, the resulting release of steam and movement of the boiler upset the brick piers that the other boilers were mounted on, and resulted in a chain reaction, that caused a total of 12 boilers to explode.



These boilers all had single rivetted lap seems. The pictures in the book match the online pictures. Remember also, that this explosion occured in the 1880's when the boilers were somthing like 30 years old. So do not expect too many modern safety fittings. That also gives plenty of time for the boilers to have found a second use after the steam generation part of thier life has finished.



Yours



Stephen Larcombe


Peter Evans
 

The key is the presence or absence of any way of determining the water level
in the boiler. If there are no places to put a water gauge, it is an air
compressor receiver. (Compressed air in mines was introduced into Australia
I think in the late 1860s). Air receivers were commonly converted from old
boilers (a Babcock & Wilcox "Wrought-Iron-Front" steam and water drum was a
favourite choice), so even this test is not conclusive. And air receivers do
have safety valves too. My money is very heavily on a purpose-built air
receiver (on account of the non-flanged ends) but I would actually have to
see it to make sure.



Egg-ended boilers are very ancient devices. The Cornish boiler was invented
by Richard Trevithick in 1812, and quickly supplanted the egg-ended boiler
and its close cousin, the elephant boiler. The big problem with egg-ended
boilers was their lack of efficiency and the fact that the hottest gases
impinged on the part of the boiler where there was potentially the greatest
deposition of sediment. Mistaking air receivers for boilers is more common
than you may think - even in reputable journals like "Australasian
Historical Archaeology" published by ASHA. One has to laugh when confronted
by a proud archaeologist standing next to a "wood-fired steam engine" (yes,
that was actually the caption!) when its ever so clearly an air receiver!



Peter Evans

Production Management, Corporate Writing and Heritage Services

0407 537 837

www.peterevans.com.au <http://www.peterevans.com.au/>

peter@peterevans.com.au



P please consider the environment before printing.
This electronic mail contains information that is privileged and
confidential, intended only for use of the individual(s) or entity named. If
you are not the intended recipient, any dissemination, copying or use of the
information is strictly prohibited. If you have received this transmission
in error please delete it immediately from your system and inform me by
return email and destroy the original message


John Shoebridge
 

My pennyworth re Egg-ended Boilers

They were quite common in NSW coal mines until around 1890. Indeed I can recall seeing a bank of them still in place (but not in use) at Minmi when I was very young.

They were very inefficient (but who cares when there was plenty of unsaleable small coal to hand) and as someone has remarked, prone to heat impingement on the bottom of the shell.

Otherwise they were easily managed, readily repaired and had excellent thermal reserve capacity to handle varying steam demand. There are pictures of them in use at several Newcastle collieries on the Hunter Photobank.

Being made from wrought iron with a minimum of internal stays or gussets, they made excellent water tanks

There was (last time I looked) one still used as a tank at a ready-mix concrete plant near Newcastle. I have suggested to several groups that it be listed for preservation but no one seems interested in such a mundane (and large) item.

From the photos I feel the one near Mt Kembla was a boiler (note the location of the suspension brackets) I trust it will long survive.

Regards
John

----- Original Message -----
From: fstamford
To: LRRSA@yahoogroups.com.au
Sent: Wednesday, February 10, 2010 7:59 PM
Subject: [LRRSA] Egg ended boiler




Hello all,

I have received the following request via the lrrsa's generic email address.

Can anyone help the enquirer?

Regards,

Frank

---------------------------------------------------

Date: 8/2/2010 22:06:51 +1100
From: Georgina Element <crella25@hotmail.com>
To: <lrrsa@lrrsa.org.au>
Subject: Egg ended boiler
________________________________________

Hi there,

I'm in Mt Kembla NSW, near Wollongong, where we have an egg ended boiler that came from the Mt Kembla Coal mine originally, but is now in a horse paddock. I was told by Graham Clegg from the Powerhouse Museum a couple of years ago, that you have conducted a lot of reserach into mines in Australia. I was wondering if you could point me in the right dirrection to find out more about this boiler: where it came from, how it was made and used...

It is made of three iron plates to achieve the diameter of the boiler. There are pictures of it on Fickr if you serach Mt Kembla Boiler. See link below:
http://www.flickr.com/search/?q=Mt+Kembla+Boiler

I've been searching on the internet for information on egg-ended boilers, but I have found out very little really.

Thank you for your time.

Kind regards,

Georgina Element


John Garaty
 

Hi Frank and all,
Some quick internet searching turned up the following links:
A photo of one as installed in the UK
<http://www.flickr.com/photos/bolou/3969208901/>

and a brief wiki at
<http://commons.wikimedia.org/wiki/Category:Egg-ended_boilers>

and one from Scotland that found a second life as a water tank
<http://www.scotlandsplaces.gov.uk/search_item/index.php?service=RCAHMS&id=113263>

My suspicion is that this boiler may have found a similar "second life" and this may be why this boiler is now in the middle of the paddock at Mount Kembla. This type of boiler may have been superceded by the early 1900's if it was in use at the mine.

Photos taken in 1902 of the pit-top after the Mount Kembla mine disaster show extensive damage to buildings near the mine entrance. These photos are also on the Wollongong Library website. One of the photos (Negative FM1/1316; FM2/105/3/3) shows what may be a boiler in the rubble.
<http://mylibrary.wollongong.nsw.gov.au/cgi-bin/spydus.exe/FULL/PIC/BIBENQ/4833386/10989832,211?FMT=IMG>

Photos of the pit-top taken in 1906, after the Mount Kembla mine disaster, show a boiler house type structure with stack close to the mine entrance.
<http://mylibrary.wollongong.nsw.gov.au/cgi-bin/spydus.exe/FULL/PIC/BIBENQ/4832277/10982632,2?FMT=IMG>
The 1906 boiler house in the photo above looks a "new build" after the disaster.

However Mount Kembla also had a kerosene shale processing plant somewhere nearby. One of the distillation pots from that plant is plinthed near the Community Hall at the top of Cordeaux Road, just below the main gate to the former AI&S Nebo (now BHP's Dendrobium) mine. For more on MT Kembla's oil shale history -
<http://www.michaelorgan.org.au/oilshale.htm>
and
<http://www.nswmin.com.au/Mining-in-NSW/History-of-Mining/Illawarra-Region/Mt-Kembla-/default.aspx>
gives the a hint to the location of the kerosense plant - "Also in 1946 the Nebo mine was established above the former shale workings at Mount Kembla." This kerosene shale plant at Mount Kembla may also have had boilers on its site.

On the light railways front, Mount Kembla was the last mine hand-worked mine in the Illawarra, with a 2' gauge cable-haulage bringing small (1-ton approx) skips to the surface until the mine's closure. One of these skips is preserved under the memorial arch at the Mount Kembla Miners Memorial at the Anglican Church in the village. These coal in these skips was dumped into larger standard-gauge wagons and lowered down the hill on an incline. The following photo (negative FM2/95/1/1A)shows one of the standard-gauge wagons on the incline in about 1912.
<http://mylibrary.wollongong.nsw.gov.au/cgi-bin/spydus.exe/FULL/PIC/BIBENQ/4834850/10828927,45?FMT=IMG>

Another guess on my part that could put a surplus boiler at Mt Kembla is that sometime either before or after Mount Kembla's purchase by AI&S in 1945, the boilers at mine would have been made redundant by electric operation of the underground haulage and the incline. On the Illawarracoal website timeline, in 1925 furnace ventilation at Mount Kembla was replaced by a fan but there is no mention of whether this fan was electrically or mechanically powered. This would have been possible from the mid-1940's under AI&S when Nebo was established. AI&S mines had their own high-voltage powerlines from the steelworks powerhouse that provided power to the mines on the coast and the fans over the back of the escarpment.

Hoping all this is of interest, and that I haven't muddied the waters too much,
Regards,
John Garaty
Unanderra

--- In LRRSA@yahoogroups.com.au, "fstamford" <frank.stamford@...> wrote:


Hello all,

I have received the following request via the lrrsa's generic email address.

Can anyone help the enquirer?

Regards,

Frank

---------------------------------------------------

Date: 8/2/2010 22:06:51 +1100
From: Georgina Element <crella25@...>
To: <lrrsa@...>
Subject: Egg ended boiler
________________________________________

Hi there,

I'm in Mt Kembla NSW, near Wollongong, where we have an egg ended boiler that came from the Mt Kembla Coal mine originally, but is now in a horse paddock. I was told by Graham Clegg from the Powerhouse Museum a couple of years ago, that you have conducted a lot of reserach into mines in Australia. I was wondering if you could point me in the right dirrection to find out more about this boiler: where it came from, how it was made and used...

It is made of three iron plates to achieve the diameter of the boiler. There are pictures of it on Fickr if you serach Mt Kembla Boiler. See link below:
http://www.flickr.com/search/?q=Mt+Kembla+Boiler

I've been searching on the internet for information on egg-ended boilers, but I have found out very little really.

Thank you for your time.

Kind regards,

Georgina Element


David Halfpenny <dh16mm@...>
 

--------------------------------------------------
From: "oztrainz" <jkgaraty@1earth.net>
Sent: Thursday, February 11, 2010 3:32 AM

and one from Scotland that found a second life as a water tank
<http://www.scotlandsplaces.gov.uk/search_item/index.php?service=RCAHMS&id=113263>
Many found use as locomotive water tanks in the UK.

David 1/2d


Peter Evans
 

Well, I'm going to stick my neck out. It still looks like an air receiver to
me - http://www.flickr.com/search/?q=Mt+Kembla+Boiler - Note the large pipe
on the top of the boiler, which in one of the detail photos can be seen
bolted directly to the shell of the vessel. If this was a steam boiler there
should be a cast-iron mounting riveted to the shell to take a stop valve.
Instead, this pipe looks rather like a delivery pipe from an air compressor.
Boilers are usually also bricked in and there is often evidence of corrosion
on the external parts of the shell where the bricks have been in contact
with the boiler, especially if the boiler has sat out of use for any length
of time. This vessel looks remarkably free of any such marks, which should
run lengthways along the shell starting about two-thirds of the way up, with
spaces between the corrosion marks to indicate the furnace gas passages.
(Air receivers are usually supported from below with three or more narrow
"U-shaped" pillars a little wider than the vessel itself - these also tend
to corrode and it would be interesting to see if there were any distinctive
transverse corrosion marks on the underside of the vessel).



In addition, there is no manhole anywhere on the top of the vessel, which
would have been a usual fitting to internally clean the vessel of sediment
if it was a boiler. Air receivers don't require manholes, only a small drain
for condensation on the bottom. I'm not doubting this vessel is old, the
pointed rivets shown in one of the detail photos are sometimes indicative of
the fact that the plates were carted into the mine separately and riveted
together by hand on the spot. The box on the end of the vessel has me
puzzled. I have never seen a fitting like this on any pressure vessel, and
certainly not on a steam boiler. It looks like a more modern addition to me,
and I would very much like to see what's inside and under it.



To my knowledge, no-one has published a history of boiler inspection laws in
NSW. (I would be delighted learn otherwise). At one point there would have
been a requirement to have pressure vessels (both air and steam) inspected.
This usually included stamping a number, date, test pressure and working
pressure on a visible part of the boiler. There are usually additional
stampings for subsequent inspections. If such stampings can be identified
anywhere on this pressure vessel, then a visit to NSW Public Records may
bear fruit with an inspection record indicating the type of pressure vessel
involved.



In the files section I have posted two Excel files (starting with the prefix
VPRS - you may have to fiddle with the column width to see all the data).
The BIA (Boiler Inspection Act) file indexes all the Victorian boiler
registrations likely to be of interest to Light Railway researchers. The
records run from 1906 to 1935. I did not index all 10,000 records for this
period because I was being paid by the Victorian Government to produce
heritage assessments of sawmill sites, so I included all the known
sawmillers and any industrial locomotive (in total only about 10% of the
extant records). The Victorian mining boiler records run only from 1927 to
about 1945 - these are apparently all that survive, although the government
inspection records should stretch back to 1897. All of the extant mining
boiler records have been indexed in this file. Both record series have been
the subject of articles in previous "Light Railways". It would be fantastic
if researchers in other States could perform a similar exercise.



I am aware that egg-ended boilers were used in Australia, but they were
rarer than more modern types of boilers. A careful re-examination of the
vessel at Mount Kembla, preferably by a qualified boiler attendant with a
good working knowledge of older types of pressure vessels, is going to be
the only way that this question is going to be settled once and for all.



Cheers,

PeterE.

.

Peter Evans

Production Management, Corporate Writing and Heritage Services

0407 537 837

www.peterevans.com.au <http://www.peterevans.com.au/>

peter@peterevans.com.au



P please consider the environment before printing.
This electronic mail contains information that is privileged and
confidential, intended only for use of the individual(s) or entity named. If
you are not the intended recipient, any dissemination, copying or use of the
information is strictly prohibited. If you have received this transmission
in error please delete it immediately from your system and inform me by
return email and destroy the original message


gould_scott <sncs@...>
 

Hi Peter,

Your description of mounting methods makes sense, as does the on-site assembly of the smaller, more easily transported components at the final location. If boilers of this type have a manhole, rivet setting from the inside during assembly would have been relatively easy (if not very noisy), but how would this be acheived on a vessel with no manhole?

Regards,

Scott

--- In LRRSA@yahoogroups.com.au, "Peter Evans" <peter@...> wrote:

Well, I'm going to stick my neck out. It still looks like an air receiver to
me - http://www.flickr.com/search/?q=Mt+Kembla+Boiler - Note the large pipe
on the top of the boiler, which in one of the detail photos can be seen
bolted directly to the shell of the vessel. If this was a steam boiler there
should be a cast-iron mounting riveted to the shell to take a stop valve.
Instead, this pipe looks rather like a delivery pipe from an air compressor.
Boilers are usually also bricked in and there is often evidence of corrosion
on the external parts of the shell where the bricks have been in contact
with the boiler, especially if the boiler has sat out of use for any length
of time. This vessel looks remarkably free of any such marks, which should
run lengthways along the shell starting about two-thirds of the way up, with
spaces between the corrosion marks to indicate the furnace gas passages.
(Air receivers are usually supported from below with three or more narrow
"U-shaped" pillars a little wider than the vessel itself - these also tend
to corrode and it would be interesting to see if there were any distinctive
transverse corrosion marks on the underside of the vessel).



In addition, there is no manhole anywhere on the top of the vessel, which
would have been a usual fitting to internally clean the vessel of sediment
if it was a boiler. Air receivers don't require manholes, only a small drain
for condensation on the bottom. I'm not doubting this vessel is old, the
pointed rivets shown in one of the detail photos are sometimes indicative of
the fact that the plates were carted into the mine separately and riveted
together by hand on the spot. The box on the end of the vessel has me
puzzled. I have never seen a fitting like this on any pressure vessel, and
certainly not on a steam boiler. It looks like a more modern addition to me,
and I would very much like to see what's inside and under it.



To my knowledge, no-one has published a history of boiler inspection laws in
NSW. (I would be delighted learn otherwise). At one point there would have
been a requirement to have pressure vessels (both air and steam) inspected.
This usually included stamping a number, date, test pressure and working
pressure on a visible part of the boiler. There are usually additional
stampings for subsequent inspections. If such stampings can be identified
anywhere on this pressure vessel, then a visit to NSW Public Records may
bear fruit with an inspection record indicating the type of pressure vessel
involved.



In the files section I have posted two Excel files (starting with the prefix
VPRS - you may have to fiddle with the column width to see all the data).
The BIA (Boiler Inspection Act) file indexes all the Victorian boiler
registrations likely to be of interest to Light Railway researchers. The
records run from 1906 to 1935. I did not index all 10,000 records for this
period because I was being paid by the Victorian Government to produce
heritage assessments of sawmill sites, so I included all the known
sawmillers and any industrial locomotive (in total only about 10% of the
extant records). The Victorian mining boiler records run only from 1927 to
about 1945 - these are apparently all that survive, although the government
inspection records should stretch back to 1897. All of the extant mining
boiler records have been indexed in this file. Both record series have been
the subject of articles in previous "Light Railways". It would be fantastic
if researchers in other States could perform a similar exercise.



I am aware that egg-ended boilers were used in Australia, but they were
rarer than more modern types of boilers. A careful re-examination of the
vessel at Mount Kembla, preferably by a qualified boiler attendant with a
good working knowledge of older types of pressure vessels, is going to be
the only way that this question is going to be settled once and for all.



Cheers,

PeterE.

.

Peter Evans

Production Management, Corporate Writing and Heritage Services

0407 537 837

www.peterevans.com.au <http://www.peterevans.com.au/>

peter@...



P please consider the environment before printing.
This electronic mail contains information that is privileged and
confidential, intended only for use of the individual(s) or entity named. If
you are not the intended recipient, any dissemination, copying or use of the
information is strictly prohibited. If you have received this transmission
in error please delete it immediately from your system and inform me by
return email and destroy the original message





[Non-text portions of this message have been removed]


Peter Evans
 

Hi Scott,



If you look where the large pipe enters the top of the boiler you will
notice a compensating ring riveted to the shell. This is designed to
strengthen the vessel where part of the plate has been cut away. The bottom
of the pipe (which appears to be made of cast-iron from the existence of a
moulding mark) has a compound-curved flange which is attached to the
compensating ring. It's hard to tell really accurately from the photo, but
that flange (and the compensating ring) appear to be circular. (I thought
about this as a manhole but, if it was a manhole, it should be elliptical so
the door to close it can be manoeuvred into place from the outside. Such
doors fit inside the vessel to resist the internal pressure). I should
imagine that the dimensions of the inside of the compensating ring would be
sufficient to admit a youth who would hold the dolly from below whilst the
remaining rivets would be closed from the top.



As explained in my last post, the photos on Flickr by themselves are
insufficient evidence to determine what this vessel really was. There is a
possibility that this could have been an egg-ended boiler, but only a
careful examination by an experienced eye will tell. (The two oddly-paced
rivets on the end-on shot, for example, have me thinking that perhaps these
have the potential to be the remains of a water gauge location deliberately
closed for a later adaptive use). If it is an egg-ended boiler, it becomes a
significant find. However, the balance of probabilities strongly favours an
air receiver until proven otherwise.



Cheers,

PeterE.



Peter Evans

Production Management, Corporate Writing and Heritage Services

0407 537 837

www.peterevans.com.au <http://www.peterevans.com.au/>

peter@peterevans.com.au



P please consider the environment before printing.
This electronic mail contains information that is privileged and
confidential, intended only for use of the individual(s) or entity named. If
you are not the intended recipient, any dissemination, copying or use of the
information is strictly prohibited. If you have received this transmission
in error please delete it immediately from your system and inform me by
return email and destroy the original message


Frank Stamford
 

Hello all,

Thank you to all the respondents to the query regarding an egg-ended boiler (or an air-receiver) at Mount Kembla.

It never ceases to amaze me the amount of expertise we have available amongst the people on this list!

I have now bundled up the responses and sent them to the enquirer.

Should there be any more responses I will pass them on.

Regards,

Frank


gould_scott <sncs@...>
 

Hi Peter,

Thanks for the explaination, the compensating ring for fitting off the outlet pipe is something used for plate reinforcement in live steam boilers, and as somone who has been lowered by the ankles down a locomotive boiler steam dome to retrieve dropped tools, can understand the employment of a youth / apprentice on the end of the dolly.

Regards,

Scott

--- In LRRSA@yahoogroups.com.au, "Peter Evans" <peter@...> wrote:

Hi Scott,



If you look where the large pipe enters the top of the boiler you will
notice a compensating ring riveted to the shell. This is designed to
strengthen the vessel where part of the plate has been cut away. The bottom
of the pipe (which appears to be made of cast-iron from the existence of a
moulding mark) has a compound-curved flange which is attached to the
compensating ring. It's hard to tell really accurately from the photo, but
that flange (and the compensating ring) appear to be circular. (I thought
about this as a manhole but, if it was a manhole, it should be elliptical so
the door to close it can be manoeuvred into place from the outside. Such
doors fit inside the vessel to resist the internal pressure). I should
imagine that the dimensions of the inside of the compensating ring would be
sufficient to admit a youth who would hold the dolly from below whilst the
remaining rivets would be closed from the top.



As explained in my last post, the photos on Flickr by themselves are
insufficient evidence to determine what this vessel really was. There is a
possibility that this could have been an egg-ended boiler, but only a
careful examination by an experienced eye will tell. (The two oddly-paced
rivets on the end-on shot, for example, have me thinking that perhaps these
have the potential to be the remains of a water gauge location deliberately
closed for a later adaptive use). If it is an egg-ended boiler, it becomes a
significant find. However, the balance of probabilities strongly favours an
air receiver until proven otherwise.



Cheers,

PeterE.



Peter Evans

Production Management, Corporate Writing and Heritage Services

0407 537 837

www.peterevans.com.au <http://www.peterevans.com.au/>

peter@...



P please consider the environment before printing.
This electronic mail contains information that is privileged and
confidential, intended only for use of the individual(s) or entity named. If
you are not the intended recipient, any dissemination, copying or use of the
information is strictly prohibited. If you have received this transmission
in error please delete it immediately from your system and inform me by
return email and destroy the original message





[Non-text portions of this message have been removed]


bjr2105
 

Hi All,

I am new to this list and see a very interesting discusion here on egg-ended boilers. As a former licensed boiler inspector in NSW, with many years of experience of old riveted boilers,I feel that I may be qualified to give some useful comments to this discussion.

It is quite clear to me that what is in the photos is of a boiler, not an air receiver. It is most likely that it has not been used as an item of pressure equipment for many years for a couple of reasons:
1) many years ago, the maximum diameter of boiler shells with lap riveted seams was limited to a maximum of 48 inches inside diameter
2) additionally,the lap seams on the boiler would have limited the allowable working pressure to 120 psi (but I am sure that this boiler would never have operated at a pressure anywhere near that high)
3) it is most likely manufactured from wrought iron; and that combined with the lap seam (and consequent grooving problems) and altered rules reagrding boiler diameter, as above, would have taken this out of service

If you look very closely at photo No. 2, we are very lucky that the boiler is sitting in its correct orientation because I believe that you can see a slight discolouration on the surface of the metal about 2/3 of the way up the shell where the brickwork was resting against the shell. Also, on the dished end, there are discolouration marks that suggest the position of the brickwork. If an ultrasonic thickness inspection were done in this area, it would most likely show up a thinning of the plate where the moisture combined with dust/ash would have worked on thinning the plate (yet another reason that these brick-set boilers proved uneconomical, due to the amount of brickwork that had to be removed to properly inspect the shell on the outside).

There appear to be three suport locations on each side of the boiler in the upper area where the drum would have been hung from an overhead structure, further supporting the claim that this is a boiler. If the vessel was made as a water tank, or an air received, the supports would be fastened to the underside of the barrel.

The riveting on the boiler is mostly steeple headed which usually indicates hand riveted work (i.e. not done with a rivet gun, but by hammering). There are other types of rivet heads on plates in the lower portion of the ends which indicates the possibility that some plates may have been replaced at some stage in the working life of the boiler.

I have no idea what the box like structure on the end of the vessel is and only a look at it would reveal the details.

However, as someone else alluded to previously, the two rivets on the end in Photo No. 6 suggest the attachment of a water gauge. Remember that at the time when these boilers were originally built, a lot of the boiler fittings that we take for granted these days (such as water gauges, pressure gauges, blow down cocks) were not used and were installed later when people realised they were needed (after the odd explosion or two...).

From Photo No. 7, it appears that the opening on top of the vessel may have a cast iron flange riveted to the barrel. I am conjecturing here without seeing the actual vessel, but this is most likely the mounting flange for a large conical standpipe for the attachment of a dead weight safety valve (a very heavy device that relied on heavy plates to hold the valve on its seat before spring devices were used). This is most likely the way that the boy who held up the rivets inside the boiler got back out after the last seam on the boiler (which was most likely the crown plate on one of the hemispherical heads) was finally riveted. On some of the very old boilers, such as this type of boiler, a manhole was not installed; it being thought that a large opening for one of the mountings was sufficient - it's amazing how far boiler design has come in the last 200 years...

Another point of interest regarding these egg ended boilers is (and this is one of the reasons for their demise as acceptable pressure equipment) is the length/diameter ratio, combined with the usual thin walls resulted in a vessel that was liable to collapse when being drained (by the formation of a small vacuum).

I hope that I have been able to add to the body of knowledge on this subject.

If I had the opportunity to have a look at the boiler in the photos, I could most likely put the whole story to bed, but I leave that to the people who have this equipment on their property.

Kind regards,
Bruce Rankin
Dudley, NSW

--- In LRRSA@yahoogroups.com.au, "gould_scott" <sncs@...> wrote:

Hi Peter,

Thanks for the explaination, the compensating ring for fitting off the outlet pipe is something used for plate reinforcement in live steam boilers, and as somone who has been lowered by the ankles down a locomotive boiler steam dome to retrieve dropped tools, can understand the employment of a youth / apprentice on the end of the dolly.

Regards,

Scott

--- In LRRSA@yahoogroups.com.au, "Peter Evans" <peter@> wrote:

Hi Scott,



If you look where the large pipe enters the top of the boiler you will
notice a compensating ring riveted to the shell. This is designed to
strengthen the vessel where part of the plate has been cut away. The bottom
of the pipe (which appears to be made of cast-iron from the existence of a
moulding mark) has a compound-curved flange which is attached to the
compensating ring. It's hard to tell really accurately from the photo, but
that flange (and the compensating ring) appear to be circular. (I thought
about this as a manhole but, if it was a manhole, it should be elliptical so
the door to close it can be manoeuvred into place from the outside. Such
doors fit inside the vessel to resist the internal pressure). I should
imagine that the dimensions of the inside of the compensating ring would be
sufficient to admit a youth who would hold the dolly from below whilst the
remaining rivets would be closed from the top.



As explained in my last post, the photos on Flickr by themselves are
insufficient evidence to determine what this vessel really was. There is a
possibility that this could have been an egg-ended boiler, but only a
careful examination by an experienced eye will tell. (The two oddly-paced
rivets on the end-on shot, for example, have me thinking that perhaps these
have the potential to be the remains of a water gauge location deliberately
closed for a later adaptive use). If it is an egg-ended boiler, it becomes a
significant find. However, the balance of probabilities strongly favours an
air receiver until proven otherwise.



Cheers,

PeterE.



Peter Evans

Production Management, Corporate Writing and Heritage Services

0407 537 837

www.peterevans.com.au <http://www.peterevans.com.au/>

peter@



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Peter Evans
 

Thanks for your contribution Bruce,



I have now been in direct contact with the person who started this
discussion, and have the benefit of some additional photographs (both
historic and detail shots of the boiler today). I agree that the single lap
seams and conical rivet heads indicate both great age and low pressure.
There is a manhole on the pressure vessel (it's just that the manhole cover
is inside the boiler which is why the bridges were not visible). I agree
that the two rivets on the end plates are a possible location for mounting
for a water gauge and would very much like to know if these rivets are
closing threaded holes.



There are some strange mountings on the underside of the boiler through
which short solid rods pass - we have not yet worked-out the use for these.
The box on one end of the vessel possibly enclosed some sort of high water /
low water alarm - these are actually quite ancient devices in steam terms
(and the steam whistle was invented in 1837 for just such a purpose). There
is also a fitting on top of the boiler which has been closed off with
round-headed rivets, indicating it was done long after the vessel was
originally manufactured.



Most telling is a shot on the inside of the vessel which shows wastage of
the plate and the rivet heads below where the water line would be and little
wastage where the steam space would be. At the moment the consensus is that
it is possible this has originally been a boiler and was later re-used as an
air receiver and possibly had a third life as a water tank. However, we need
to know for sure because this vessel is in public ownership and if it has
been a boiler it will be a rare survivor and money will be spent on
conserving it.



Bruce, I will contact you off-list to continue this discussion regarding a
history of steam legislation in NSW.



Cheers,

PeterE.



Peter Evans

Production Management, Corporate Writing and Heritage Services

0407 537 837

www.peterevans.com.au <http://www.peterevans.com.au/>

peter@peterevans.com.au



P please consider the environment before printing.
This electronic mail contains information that is privileged and
confidential, intended only for use of the individual(s) or entity named. If
you are not the intended recipient, any dissemination, copying or use of the
information is strictly prohibited. If you have received this transmission
in error please delete it immediately from your system and inform me by
return email and destroy the original message