Extracts from the National Steam Centre Newsletter

October Issue 585 2019

Far North Cochran Queensland Relics Boilers

Also in this Issue

Clive Windley demonstrating his recently sumpathetically restored Vintage Workshop filing machine

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The Discovery It was languishing under the old railway arches at the historic Coalbrookedale iron works in Iron Bridge Gorge in Shropshire and rather out of context to the main displays of a 300 year old smelter . I snapped a few photos including the makers plate and on studying them months later at home was surprised to find it was built in 1956 by Cochran & Co, Annan Ltd Scotland, No 20394 . Maximum working pressure 100 lbs size 10 . Surprisingly recent considering the iron works had it’s heyday in the early 1700s. Here I was thinking it must have been something from the industrial revolution so what was it doing here?

The Marine Connection Back at our Steam Museum I mentioned it in passing to Marine Engineer Bill McRobb from the Lyttelton team as it somewhat resembled their Farrar boiler they have

just installed. Bill was certainly aware of them as he had come across them on ships as auxiliary boilers . He mentioned one of their attractions was the vertical layout as it reduced the floor space taken up in the engine room .

An unusual type of boiler caught Warwick’s eye during a UK Vintage Machinery Tour. It was an unfamiliar type and had a number of unique features which raised the question why it was so different and was it actually any good or just the result of some ones whims and fancies in the early days when boiler design was still evolving. This started the process of discovery and over a couple of years of piecing snippets of information, from many different sources, slowly the picture emerged of a type of boiler widely used but seldom seen.

The Cochran boiler under the railway arches . The most obvious departure for a typical vertical boiler was the smoke box on the front .

Going round the back revealed a horizontal bank of fire tubes with a brick lined combustion chamber fed from a

hemispherical furnace underneath

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The fact that they were quite tall was not an issue as ships with vertical reciprocating engines needed high ceilings anyway . This point was well borne out by taking a glance at the Farrar boiler beside the Littleton engine room display . So a lyttle bit more info had been found but still not enough for a story.

The height of vertical boilers in relation to there

floor space is apparent in this photo of Bill McRobb steaming the Farrar in our ship’s engine room display.

A Surprise bit of Information Not much was thought about Cochran boilers until several months later when doing museum duty at the Steam Center. I noticed a middle aged lady showing a keen interest in our steam displays while her gentleman partner was standing around outside looking board witless . It is usually the other way round . Anyway I engaged her in conversation and it transpired she was involved with boiler design in the UK so on the off chance asked her did she know about Cochran boilers . Her eyes lighted up and confirmed they were often used as auxiliary boiler on ships the main reason being vertical they fitted in better and in fact were still in production. Still I thought, being odd there must still be some other reason. All she could suggest that cronyism was not unknown in the UK with people specifying equipment for products sometimes having preferred suppliers for various personal reasons. The Interweb With my interest raised I decided to do a bit of research on the google machine. Cochran &Co now present themselves as “Cochran Energy Solutions Worldwide” and have been making and servicing boilers for over 135 years. Main Works are located in the very south of Scotland on the Annan river were it enters the Solway Firth just above the border from Carlisle . New Designs are concentrated on these days. Because of the high cost of fossil fuel it is necessary to constantly improve the efficiency of steam and hot water generation Upgrading Older Plant is another part of their business since the long working life of Cochran boilers means it is worth rejuvenating them to modern standards and convert to automatic firing for reduced operating costs Fuel Conversions from traditional heavy oil to utilize gas or energy recovery for almost any boiler Boiler Repairs to all types and makes of boiler providing a fast response all round the world So from cochran.uk.com it seems they are still alive and kicking having gone truly international - unusual in the UK . Rohan’s Collection While being good information that did not really reveal much about their traditional boilers. The

breakthrough came with information from Rohan Lamb’s collection of historic boiler books and brochures. Cochran sales information including excellent coloured illustrations and views of their products and works some of it going back to 1904

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WHAT is SPECIAL ? At first glance they looks like a modified form of the simple vertical drum boiler typically fired on solid fuel but there are many special features. The Hemispherical Surfaces The domed top is first noticed . Being curved this surface does not require staying to resist the pressure, as in normal boilers where these surfaces are flat . Also there is no chimney passing through the center simplifying construction Fire box at the bottom Closer inspection show the fire box at the bottom also uses a hemispherical crown sheet as opposed to the usual flat sheet. In addition to the larger heating surface area it made cleaning easier . In the larger sizes this was specially mechanically pressed from one plate resulting in the hemispherical surfaces having neither riveted or welded seams exposed to the fire giving greater resistance to wasting .

Fully Spherical Fire Box With oil or gas firing , since no grate is required the fire box can have a dished wet bottom as well . This makes it fully spherical giving greater surface area for increased heat transferee as well as making it stronger . Fully spherical furnace allows working pressures up

to 250 lb/ sq in without stays

Combustion chamber A short tube leads out of the fire box to connect with the

combustion chamber on the back side of the boiler barrel. Combustion of the gasses are completed in this chamber before they enter the fire tubes. The refractory lined door on the back of the combustion chamber can be easily opened for tube cleaning and maintenance. See coloured section at top of page

This section of a Standard Coal fired Cochran Boiler showing appearance and position of normal fittings and mountings is similar to the example first seen at Coalbrookedale.

DOMMED TOP

DOMMED FURNACE

COMBUSTION CHAMBER

HORIZONTAL TUBES

SMOKE BOX

FLUE

Coloured section of Boiler from Rohan’s Cochran brochure

The patent hemispherical seamless furnace of boilers over 4’ 6” dia specially suitable for resisting

extreme heat of burning oil fuels. Obviously easy to make if you have the special hydraulic press.

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Horizontal Fire tubes The Special features are the fire tubes . This nest of fire tubes are placed horizontally so the hot gases pass from one side of the boiler to the other giving easy access from the combustion chamber on one side and the smoke box on the other for cleaning and repair. The real advantage of this design is the greater heating area of the large number of small tubes . This gives a higher steam output and heating efficiency than with a conventional vertical arrangement which has a fewer large tubes and in some designs not even fully covered with water. Chimney Runs up the outside of the boiler rather than passing through the top plate which then leaves the surface of the chimney above the water level exposed to hot gases. Comparable vertical boilers . The Cochran on the left has a large number of horizontal fire tubes all fully below the water level . Traditional vertical boiler somewhat similar to the Farrar has only 2 big dia water tubes . SUMMARY So that answers what is special about there traditional Cochran boilers but since they are still going strong when the traditional design has long gone there must be some other advantage they offer for today. The breakthrough came when MSTEC member Chris Dixon recently donated a book Marine Steam Boilers - J H MILTON - Marine Engineering series published 1974 which had a whole section on waste heat recovery . Waste Heat Recovery This is especially applicable in modern ships powered by diesel engines as they still need low pressure steam and hot water for services such as heating and refrigeration but no longer have a main boiler from which this can be drawn. Enter the

composite boiler This is one that can gets it energy from either the waste heat in the engines exhaust or through oil firing or both . Composite boilers. Principle In a conventional internal combustion engine only about 30 % of the energy in the fuel is available at the crankshaft as work. Another 30 % is lost in cylinder cooling and mechanical friction . Worse another 30 % goes as waste as heat up the exhaust which can be as hot as 400 deg C . If you can catch some of this you are virtually getting something for nothing.. This is where the Cochran boiler, with it’s horizontal tubes, comes into its own. By providing an additional nest of horizontal and passing the exhaust gases from the diesel engine through these the vessels requirements for low pressure steam and hot water can be met with little additional equipment if you have a Cochran boiler. Arrangement The Boilers second nest of tubes is located in the barrel above the main nest which makes the boiler slightly higher. Separate inlets and outlet ducting for the engine’s exhaust are provided and by placing the boiler close to the engine these can be kept very short. Unfortunately it is not practical to further simplify the installation by using just a single set of tubes as this would rule out using both heat sources at once as there is not enough oxygen in engine exhaust to support combustion . For the same reason the chimneys are kept separate to avoid backflow

Waste heat recovery cont. ——->

Single pass Composite Cochran boiler Marine Steam Boilers

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Operation When underway at sea there is plenty of heat in the exhaust to provide all the requirements for hot water and steam and often enough to run a turbo generator for producing electricity without the need to fire the Cochran boiler at all . Under these conditions the lower tube nest , which is used when fired on oil , is kept flooded with water. Of course when in port and the main engines are not running steam is still required for the above services so the Cochran can be fired on fuel oil in the usual way. All in the one piece of equipment. with the addition of very little more equipment and taking up no more floor space than an ordinary auxiliary boiler . Conclusion The enduring success of Cochran's is having a boiler design that with the addition of very little extra equipment and taking up no extra floor space has been able to be adapted to modern requirements for waste heat recovery. With this improved efficiency, the adoption of welded construction and modern control system Cochran has been able to move with the times and are still practical today as well as being supplemented with a range of horizontal units. Post Script Cochran Boilers crop up everywhere… Since starting this article a couple more Cochran boilers have been discovered. The first is mentioned on their website. Last year we were contacted by a wreck diver from the Netherlands

who dived on an unknown wreck in the North Sea and found a Data Plate that came off one of our boilers! We are currently trying to see if we can find the boiler records to help identify the wreck in the North Sea Date: 06/02/2019

The plate from the sunken ship for boiler 4524 1907

The second was discovered by Bill McRobb in the boiling down works in Burketown up in the gulf country Although Bill saw no nameplate it had the horizontal tubes flue from the furnace leading him to think it was a Cochrane. He comments These were very popular boilers used with the opposed piston Doxford ship's engine. The MV Mundoora is the only ship I sailed on with a ( composite ) Cochran. It was very basic, and we fired it with an oily rag on a long rod.

The boiler Bill came across in the abandoned Boiling Down works Warwick Bryce 18/09/2019

Bill McRobb photo

Acknowledgements Cochran Brochures—Rohan Lamb’s Collection Marine Steam Boilers - J H MILTON - Cochran Boileres website

Marine Steam Boilers Engine

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The Railway The railway group have been taking the opportunity of a few better days lately to get stuck back into track construction. Kerry Shall watches while, John Pattison and Barry George position rails for attachment to the sleeps. Railway Manager Rob Worland reports with 51 panels done only about 12 more sections need be assembled once the rails have been rolled and adjusted with the hydraulic bender . Sufficient fasteners are on hand minimising expenditure for this month..

Embankment earthworks have been on hold because of on going rain over the last few months . The embankment still needs to be raised up to 1 meter in one place and the batter profiled. This will require obtaining fill from outside. While there has been no further progress on a new boiler for Frankland Flyer the Diesel loco is making good progress. New Diesel Loco Peter Lynch and Geoff Lintott have spent a lot of time firming up the concept including assembling a mock up in the back of bay 5 to determine the location of the key components

such as engine , hydraulic tanks and radiator. This has

allowed details of the engines mounting and support brackets for the oil tank and dashboard to be worked out. Also a lot of

time has been spent establishing what is available in the way of hydraulic drive and brake system components. One concept for the brake system . The intention is to have it compatible with the air apply system on our existing carriages. The locomotive will have a mechanically operated emergency brake as a backup to comply with the requirements .

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Our White Steam Car While not much visible is happening , because we are being mindful of the need to complete some 1/2 finished jobs before starting others, that does not mean nothing is happening behind the scenes. A lot of work by Bob Atkins and his associates went into the investigation 3-D metal printing of a new burner plate. In the end the cost blew out with no guarantee of a successful outcome so more conventional methods were turned to . Following enquiries to the Jay Leno team it was found out a batch was being made in the traditional way on the Isle of Mann. On making contact it was established a batch of 10 was planned and there would be no more after that and only 2 were unspoken for. Now as one of our early Presidents pointed out in our game often you have to grab a chance as it passes as once it has gone there wont be another one. After a bit of soul searching and a look at finances an order was placed. Just in time as it turned out as we have been assigned number 9 . The burners are being supplied in the order payments have been received so it will be some time before ours is ready but if we had held off until we were ready for it we would have missed out. Anyway during this investigation an advertizement for a steam car caught my attention . It is a Brooks , a bit newer than ours but in very similar condition , mechanically complete but no body or tyres . The asking price UK £ 35,000 so ours would be not too much different

Also noted was a spare engine from the same vendor for UK £ 3,000 . This engine was described a enclosed twin cylinder horizontal engine for mounting directly to the back axle of a Brooks Steam car. A spare engine in storage for many years.

The Brooks engine

definitely not enclosed , in fact the whole plant layout closely resembles that of a Stanley and not as an advanced design as the White.

Vintage Workshop—Working Clive Windley has got the THIEL filing and sawing machine up and running . See front cover . A conventional hand file or saw blade is placed in the machine and stroked up and down while the work sitting on an adjustable table is presented to it. Stopping and starting is controlled by a foot pedal leaving both hands available to manipulate the work .

A brass plaque gives the number of strokes for different materials and finishes

Willans Diesel This month it has been mostly fabricating and maching . Bottom End Bearings First the pouring of the white metal bearings has been completed and these are over with ACE Engineering with machining well underway. Phil and “Crazy” planning the job.

Preston Services ad

Ian Malcolm pics

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Baring Stand John Mills using his powerful hammer drill to install the replica baring stand he has fabricated for turning the Willans over .

Oil Slinger Rings Terry Duggan on the Vintage Workshop’s Ward lathe parting off blanks to make replacement oil slinger rings for the Willans camshaft . Luckily one could be found for use as a pattern as we have no detailed drawings.

Bill McRobb has been wandering along the Savannah Way on his Northern pilgrimage this winter. The Queensland section stretches from Cains on the coast West to the NT border passing through Burketown. Along the way he came across a number of relics of the steam age that he snapped for our interest.

Cumberland Chimney 400 km inland from Cairns this is all that remains of the Cumberland gold mine Established in 1872 it was a highly mechanised operation with steam powering the batteries, winding gear and pumps to process ore drawn from 1000 feet underground . A thriving town of 400 people sprung up to service the mine with production peaking at 11,500 ounces in 1886 . Like most of these ventures it was short lived and began declining once all the easily won gold started to peter out resulting in the town being abandoned by 1897. .All that is left to remind us of the past is the substantially built

brick chimney.

S S S S S S SS S S SS S S S S SS S S

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Rider Hot Air Engine Further west in a park at Georgetown Bill spotted a Rider Hot Air Pumping Engine .

No it does not pump hot air but rather small volumes of water typically for domestic use. It works by heating air to drive the engine which strokes the water pump

The diagram shows the key parts

The engine has a cold water jacketed cylinder on the left while the one on the right is kept hot by a stove underneath . A displacer shuffles the air back and forth between the 2 cylinders causing alternative expansion and contraction of the air which drives the power piston. The small reciprocating water pump can be seen on the left side of the cold cylinder. Although in bad shape with a split fire box the essential parts are still there. ( Working ones will be on at the Lets Make it Exhibition )

Burketown Boiling Down Works 530 km further west are all that remains of the ill fated Boiling Down works. Thy were established in 1867 with the plan was to cure beef in brine for Batavia but was not successful and closed in 1870. It was started up at least 4 more times but each time shortly folding due to drought, cattle disease, a disastrous fire , the high cost of shipping and finally by the end of 1891 because of the high price being paid for cattle by competing buyers. Today although the site has a heritage listing all that remains are derelict pieces of machinery most notably a variety of boilers.

. Two Burns & Twigg , Rockhampton boilers Described as Lancashire type on the heritage listing but having only 1 flue I would have thought they were Cornish.

Bill McRobb pics

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Gregory Further along the track and further inland at Gregory was another Rider Hot Air Pumping engine. T his picture tells a story. The engines pumping days are over with cracked cylinders probably from build up of lime in the jacket from hard water. Surrounded by a parched environment and abandoned buildings life without water was too hard out here.

Amazingly the makers plate was still intact claiming it to be an Improved model.

It does not say what the improvement are but it has decidedly more style to the casting so suppose it is a later model. Made by Rider—Ericsson Engine Company New York , Philadelphia , Chicago, Boston , USA and listing patents from 1875 to 1880 and stamped .Size 8 inch , No 1182 . The stampings are highlighted so some enthusiast has been interested.

One with an unusual cast flywheel with rim of circular cross section and cast in spokes described on the

internet as having a hollow flywheel !!!

Of course there is the Cochran boiler mentioned earlier

Internet pic

Twigg & co Rockhampton on the firebox hole surround . According to the internet there are a couple of horizontal steam