How long did they go between full boiler overhauls

[Londontram]

With steam preservation in today's world the boiler has to be fully stripped of its tubes every 10 years with correct me if I'm wrong the possible need for a few tubes being withdrawn at about 7 years.

 

 Back in the day what was the time period between major boiler works.

  I realise there was a pool of spare boilers for each major class but from time to time you come across the comment that "this or that loco kept the same boiler and firebox its whole 30 year life.

 

 Another example is the small group of Scottish locos that were taken from museums and put into service for about a 7 year period in the late 1950s early 1960

 

 I can find no mention of these some of them having not run in steam like the Caley single as one example since the 1930s having any sort of boiler overhaul before being steamed again retubing being an investment I would doubt BR would have sanctioned on such a scale in the late 1950s.

 

 In some cases it must have been 20 years and the boilers were well used when they went into the museum's in the 1930

 

 So are we to believe that BR as was took the view that as long as they appeared sound and steam tight then a limited life extension of 7 years over an already 30 year or so tube life was exceptable?

[Londontram]

Moderator- sorry I  inadvertently hit the down load butten twice, could you please remove the other posts with the same title. Thankyou

Edited March 28, 2020 by Londontram

[jim.snowdon]

BR had a considerable experience in the management of locomotive boilers, built up in parallel with the development of the steam locomotive. The same is not true of the preservation movement, however skilled the individuals may be, with the result that a greater degree of regulation was considered necessary by the Railway Inspectorate, as the safety authority.

 

US practice is rather different, possibly as a result of commercial competition and standards cutting, in that there are Federal regulations determining when boilers must be retubed and examined, based on time alone.

 

Jim

[avonside1563]

There's a few questions there, some of which there will be more qualified people on here to answer. However one often misunderstood fact is repeated in the first paragraph of the OP. A boiler certificate does not last 10 years, or even 7 years, it runs for 14 months consequtively  from the date of the initial hydraulic inspection when a boiler is being returned to service. The maximum length of time a boiler can operate without being stripped is 10 years (with the option of a short extension, usually no more than 6 months, dependent on a detailed inspection and other factors). However a boiler can be stopped at any point during its life span for repairs or a complete overhaul should it be necessary.

 

The lifespan of a boiler depends on a number of factors including the type of water and any treatment of the water, the cycling of the boiler from cold to hot and back, how often and well the boiler is washed out, How the boiler is managed when in steam, etc. Other factors also include the design of the boiler and the materials used in construction, some boilers built with copper fireboxes and brass tubes were known to last for well past 10 years before requiring overhaul in years gone by.

[Siberian Snooper]

When I worked for MOD(N) at Devonport marine boilers, both smoke tube and water tube, had a full retube every 10 years.  At 5 years 10% of the tubes were removed and wear and waste tested. IE. the removed tubes were cut longitudinally in half so that the wall thickness could be measured and the internals checked for pitting. If all was well then new tubes were fitted, but if a problem was found then a few more tubes were removed and checked around the problem tube.

 

The 10% were a random selection in different areas of the tube bank, to give a good cross section sample. In water tube boilers this meant taking additional tubes out to get to the selected tubes.

 

 

[Siberian Snooper]

Avonside is correct, boilers are required to be hydraulically tested every 14 months maximum, MOD(N) was usually around12 months, and a visual inspection carried out as best as possible.

 

 

 

[jim.snowdon]

It is all very well quoting modern practice, and practices from outside the railway, but they are not necessarily an accurate reflection of what the railway companies were permitted to do, not forgetting that operational locomotives were outside of the Factories Act, unlike boilers used in Factories, Shops and Railway Premises (ie those in workshops and as permanent fixtures in sheds).

BR stopped operating locomotive boilers 52 years ago.

 

Jim

[H2O]

Operation in preservation and when steam locomotives were used by BR are completely different.  Before withdrawal by BR a front line working steam loco would ideally be in steam for over a week, then have a hot washout and return to service.  When being used the loco would be worked reasonably hard for an extended time meaning a stable operating temperature.  On going maintenance would be routine and I'm sure the crews and others in the shed looking after engines would spot the tell-tale signs of something more serious needing doing.  The time between major work would therefore be quite variable.

 

In preservation locos are operated by a variety of crews with even the collective knowledge of the most experienced and knowledgable not up to what was known before.  Engines often go stone cold in the week and are then fired up the night before operation which is usually a few comparatively short blasts followed by a lay over.  Assuming everything else is working ok it is these heat cycles (both in and out of steam and also when being used) that typically puts the most stress on a boiler and leads to work needing to be done on a more regular basis - hence the regulations now being different to those in the past (together with increasing health and safety based rules).

 

Edit - Accidentality  posted when incomplete - doh!

 

Edited March 28, 2020 by H2O

[Steamport Southport]

21 minutes ago, jim.snowdon said:

It is all very well quoting modern practice, and practices from outside the railway, but they are not necessarily an accurate reflection of what the railway companies were permitted to do, not forgetting that operational locomotives were outside of the Factories Act, unlike boilers used in Factories, Shops and Railway Premises (ie those in workshops and as permanent fixtures in sheds).

BR stopped operating locomotive boilers 52 years ago.

 

Jim

 

Thirty odd years.

 

As well as repairing and operating most of the mainline certified National Collection/NRM locomotives they also had the VoR Tanks.

 

 

 

Jason

[The Stationmaster]

Asking about the life of a boiler between overhauls is rather like asking about the length of a piece of string - it depend on numerous factors and which component is being talked about.  For example Swindon was managing to get a total life before renewal of 800,000 miles, and sometimes more out of boilers by the late 1930s whereas the estimated figure 20 odd years previously was an estimated 400,000 miles.  But by that mileage the boiler would have been retubed numerous times, the firebox would probably have been restayed several times, parts of the firebox would have been renewed, and so on.

 

So looking at it from another perspective you could perhaps relate visits to main works to boiler lifts and by the 1930s the GWR was managing 80,000 miles for many of its engines.  But boiler condition also depended very much on water and the natural chemicals it contained around the network plus work carried out at running sheds plus condition reports submitted by the Boiler Inspectors.  What didn't exist - except estimated achievable miles run between General Overhauls - was a sort of time frame limit on boilers in traffic.  For instance the GWR procedure was for a stay to be tested weekly on all fireboxes and if there was a bad one, or of course if leaks were occurring through the stays, the amount of corrective work required would lead the Boiler Inspector to recommend the course of action he thought necessary.  Sometimes that might put a calendar limit, say 28 days, on the boiler before it had to be dealt with but such a limit might not be put on an engine approaching its shopping mileage. 

 

So on the railways as they were in the age of steam there is really no definitive answer and you need also to understand that as the rundown of steam commenced things changed anyway with depot Boilersmiths carrying out repairs to faults and wear which previously would have led to an engine being shopped for boiler work.  as for stuffed and mounted museum pieces it all depends on condition.  when 'City of Truro' was assessed for return to steam for GW 150 it was found that all the stays were wasted below usable tolerances - because the boiler put onto it before it went into Swindon Museum had not been overhauled.  Why should it have been - the engine was going back into a museum?

 

Don't forget also that nowadays the Boiler Inspector works for an insurance company and he will also impose limits and standards in relation to the risk carried by the insurer.  That didn't apply in BR days when the concern didn't carry insurance for boiler failures.

[IWCR]

Retubing a boiler was not considered a major job, it could be done fairly quickly with the boiler still in place on the frames. Likely the Scottish preserved locos were retubed, if not fully a selection would have been removed and checked with a partial retube as indicated.

Locos in traffic would be dependant on use, conditions etc, looking at some express loco types such as on the East Coast Mainline shows some boilers being exchanged at periods as short as 5 years with major works being required such as replacement fireboxes.

 

Pete