It was back in 2002, when the well known dealer of all things steam, here in east Kent, UK, contacted me to say he had just acquired a steam machine of a very unusual design, and asked would I care to pop down and take a look.
The portable steam engine, which at the time was painted in red primer, had recently been purchased from an auction house and was thought to have spent some of its working life in an east African country. It was certainly of a most unusual design, with a vertical cross tube boiler and a single cylinder engine with a piston valve. The engine sat on top of what appeared to be a gearbox which, via a lever, controlled power to a pulley wheel on the outside of the large right hand rear spoked wheel. Wheels of a smaller size were fitted to the front of the machine. There was a small brass plate on one side of the firebox wrapper plate which seemed to indicate it was of foreign manufacture, but it was hardly legible, so did not give much away.
It was only in the early months of 2008 that this engine was properly identified, when a collector came from Germany and purchased the engine from the dealer. He identified it as being by the firm of Rudolf Wolf Aktiengesellschaft of Magdeburg-Buckau in southern Germany.
Rudolf Ernst Wolf (1831-1910), started his firm in 1862 by manufacturing farming equipment, in a similar fashion to British firms such as R. Hornsby and Sons, and Ruston Proctor. The firm became well known on the Continent for their quality machinery, but closed its doors in 1945. It is interesting to note that Wolf entered into an agreement with H. Lanz AG in 1926, for the construction of threshing machines. On finding who the manufacturer of this engine was, I decided to carry out some research, and contacted two archives in Germany, requesting whether they may have had some data on this portable.
After a while I received two replies; one could not help, but the second sent me a copy of the sales brochure of 1926 giving a detailed description of the HeissDampfmotor-Lokomobile (Hotsteamotor) Modell MF6. Though it has a sticker on the front of this delightful catalogue which states that this portable received one of the highest awards at a big agricultural show at Breslau, Germany, in that year, there is a train of thought that it was put out by the firm at least a decade or so earlier, but I have not been able to confirm this. The opening statement states the following:
“The present unfavourable economic situation has, for a long time, forced all machinery manufacturers to improve their engines to drive machinery, with a more modern and extremely economical and interdependent engine, and of course one that is affordable to farmers and other users in these difficult times. (Somewhat shades of today’s economic climate?) Therefore, the R.Wolf AG concern has built a new type of engine to fill all user requirements. This portable engine, which has a totally enclosed engine and gearbox of a most unusual design is ideal for use on the farm and is also most suitable for driving windmills and water mills - when wind and water are not readily available. The vertical boiler which, incidentally, runs at 234 lbs (16Atms), has a fully stayed oval firebox and a cross tube boiler with a three coil superheater in the base of the smoke box, and the steam valves are of the twin Salter type. A soot blower working at high pressure is also fitted so the smoke tubes could be quickly blown through, to clear out any blockages. The firebox is designed to be able to use virtually any material which could be burnt, and could also be fitted with oil burning equipment if required. But, most interestingly, the engine, a single cylinder with piston valve, is mounted over the circular rear axle which also houses the gearbox. This design is to one of the company’s special patents. The gearbox is of the totally enclosed design for protection against external influences, dust and humidity, guaranteeing a very long working life. The whole unit is mounted on steel wheels for easy manoeuvrability. It is also stated that this engine could, if required, work at 40% overload and above, for long periods.” (Quite a serious claim).
Lighting up times were advised as being very quick - so it could be put to work in the shortest possible time. Other interesting claims for this machine were that it was fitted with large wheels at the rear and about half the size on the front so it could be easily pulled by one horse using the correct shafts, as its total weight was 2 tons, or could be moved with two or three strong men. I would have hoped that they would have had a good breakfast in the morning to boost their strength!
It would appear that this portable was really a ‘special’ for use in such work on the farm as the potato harvesting season, where it could be brought near to the top of the rows and the steam lance from the boiler could be used for cleaning and drying the potatoes.
Of course, the company ran through a list of the eight most important advantages in having such a Locomobile, including low purchase costs (the brochure hints that special deals were offered at the time for easy purchase), quick readiness for use, a large reserve of power, high economy with differing fuels, high durability, long working life, easy operation and, finally, easy transportability of the engine. At the bottom of this brochure, the firm indicated they would send out any details of their machinery on request and would also send a representative out to the farm at no cost to the prospective client; they were hard times in the mid 1920’s for the farming community in Europe.
It is a pity that currently, we do not know how many of these interesting Locomobiles were constructed - especially from the firm of Rudolf Ernst Wolf, AG who operated though two World Wars and certainly manufactured many high quality pieces of machinery. But what is now certain, is that, in time, this engine could quite likely be put back into steam in Germany in the coming years.
After World War One, the German state was called to account for its actions during the four year conflict, at the now famous Treaty of Versailles in June, 1919, just outside of Paris. This lengthy document, drawn up by the Allies, ordered the State to pay vast reparations to the countries for damage caused by the conflict.
What is not generally realised today, is that these reparations went as far as imposing restrictions on all the machinery manufacturers in Germany in relation to who they could trade with, worldwide; this was, of course, a catastrophic restriction for their engineering base. For example, they could not trade with any of the countries within the dominions of the British Empire, Australia, New Zealand and Canada, as well as the overseas colonies that Britain administered, which also included the French possessions around the globe.
It would appear that some of the countries in South America were not included in the list, and it is possibly for this reason that there is so much German machinery of all types still extant there which are now being imported into the UK. The total bill charged to the German state in 1919 by the main Allies, was 227 billion gold Marks - a huge sum even for those times.
The other steam portable, at the same location, was by the famed firm of Sentinel, perhaps best known for their Steam Trucks of which a number are regularly steamed in Australia today. This firm commenced building ‘waggons’, as they referred to them in 1905, and finally stopped in about 1933, though a batch was built to special order in the early 1950’s. Like the R. Wolf and many other companies in the same line, they were feeling the pinch by the late 1920’s, and tried to introduce a portable engine using the boilers and engines from their waggons.
Of course, they were somewhat late in the day with their efforts, for people such as W. Marshall and Sons, Gainsborough and Clayton & Shuttleworth, both in Lincolnshire, had been building portable engines in vast numbers in the 19th century.
The firm of Alley and MacLellan of Polmadie, Glasgow, opened a new works in London Road in 1880, having manufactured engineering machinery during the preceding 20 years. It is sometimes not generally appreciated that they also offered many other differing pieces of quality steam machinery such as boilers, steam winches and ships steering engines (of which over 1,400 were manufactured in both vertical and horizontal double cylinder forms), high speed compressors, lighting plants, and stationary and marine steam engines, etc.
River craft and lake steamers were also produced in kit form and shipped worldwide; several are still in use today in Africa. It was just before World War One, that the firm was in need of more space, and a move was decided upon. A number of locations were considered, but the town with space to fill was Shrewsbury, Shropshire, south west of the big industrial city of Manchester. A brand new factory, known as the Sentinel Works was constructed, with a worker's village opposite. Each house had hot water, a luxury unheard of at the time.
In 1923 and 1924, patents were laid by Mr S.E. Alley and Mr K.Willans for a design of steam portable engine and, naturally, it was designed around their Sentinel boiler and horizontal engine. In the first instance, it was known as the 50hp model, but later became the 40-60hp. It used the double cylinder engine which were used on the waggons, with a bore of 172mm and stroke of 299mm; of course, no differential was required. A Pickering governor was also fitted for work on the belt. Various modifications to the engine were carried out to enable the engine and boiler to fit the U iron steel frame - a heavily made construction.
The boiler was similar to the standard wagon type boiler, with the square section firebox, and sets of tubes crossing at right angles. Two more sets of smoke tubes were added, making 80 in all, and the superheater had an extra coil fitted, as it would compensate for the inferior fuels that would, no doubt, be used in the exported engines. In fact, it was expected that these interesting portables would be mainly for export worldwide and, indeed, more than half did go overseas.
As with most portables, the funnel could be lowered via a hinge when moving from job to job. The engine was fitted with a set of cast steel wheels, and braking was supplied by the usual wooden block and screw-down arrangement to the rear wheels. In 1925, this model was offered by the firm for £500, complete and delivered to the nearest port for shipping, though there were various other fees and charges for items such as stripping the engine down into smaller units for delivery to distant locations with poor infrastructure, such as roads.
The single cylinder engine which is presently being offered for sale, is build No. 5686 of 1925, rated at 20-30hp. It is in need of extensive restoration, and a number of vital pieces will be needed to get her up and running again. This engine design is, in effect, one half of the engine which was fitted to the Super Sentinel wagon of the same period, but the crankshaft was a forged round bar without balance weights, and it differed somewhat from the wagon engine. In particular, it had only one camshaft, and all four valves were mounted below the engine, instead of the inlet valves being above and the exhaust below the cylinder. They were operated by a sliding camshaft, which was driven though gears off the crankshaft via a lever, and two flywheels, both of 2ft 9" diameter, were fitted at each end of the crank, and balance weights fitted into each rim. The chassis of this rare portable is much narrower than the one fitted to the 40-60hp twin.
This boiler is also the same diameter as the one on the twin machine, though lower in height and, again, sported a superheater. Both sizes of portables were being sold at the time, at a great deal less than other makes of contemporary designs, and the last price quoted when construction ceased, in March 1929, was £368.50, less 5 per cent for cash for the single cylinder version. Without fuel and water, it weighed in at only 2 tons 18cwt. When production ceased in 1929, it is believed that only 82 portables were built, of which 50 were of the single cylinder design. A total of 56 were sent to their agent in South Africa, three went to Kenya and six to India.
I would especially like to thank Dorothe Steidinger, an Austrian friend who kindly translated the R. Wolf AG pamphlet for me.
Further reading on the history of the Sentinel Company can be found in the two excellent books The Sentinel Volume 1, 1875-1930 by W.J. Hughes and J.L. Thomas, and The Sentinel Volume 2 by A.R. Thomas and J.L. Thomas, published in 1973 and 1987, respectively.
Especially written for The Old Machinery Magazine, Australia. *Tim Keenan, UK.
