Friday, July 16, 2010

MINI STEAM JEEP (STEMKA) 2




Apart from the steering wheel, the instruments and controls consisted of pressure gauge, speed and distance meter, foot and hand brakes, foot and hand throttle controls, engine cylinder lubrication pump and feed-water metering and bypass valve. Other controls included a boiler scale-trap blow down, chimney blower jet valve, feed-water priming pump, engine reversing and notching up lever, cylinder drain cocks lever, fire door, furnace air control and excess steam release valve. The cylinder drain cocks were made in the form of pop safety valves with variable spring loading from the hand lever and notched quadrant. If they were momentarily set at below boiler pressure they went off like small bore rifle shots.

Main dimensions were, wheel base 52”. Track 40”. Overall length and width were 70½” and 46”. The furnace extended rearwards from the generator section with the hinged fire door on top. The cylinder drain cocks lever, the hand brake, and the furnace air control levers were grouped close to the reversing lever. Apart from lighting up there was no smoke emission. The occasional burning of macadamia nut shells did create a little brown smoke as well as plenty of heat. Touring around the local streets produced memorable events. One found one’s self leading two or three cars showing no tendency to pass and they would loiter alongside. On one occasion pulling into a friend’s home and treating him and neighbours to rides up and down the street the fuel supply ran out with still a kilometre to get home. No problem, kindly people rummaged in their garden sheds and enough scraps of wood and pine-cones quickly appeared to continue the entertainment and complete the journey. They were apologetic over the tree bark included but to Stemka’s boiler that was good hot ember producing fuel. A friend, also a steam buff who frequently rode with me shares the memory of a Sunday afternoon jaunt about the village when we had to stop at an intersection for cross traffic. There was a full head of steam causing the release valve to blow off the excess which due to the cool air temperature and no breeze, enveloped the vehicle in a fog much to the obvious astonishment registered by the occupants of passing cars.

After six years of enjoyable driving and tinkering I became dissatisfied with the temperamental characteristics in this application of the flash type generator. Schemes for various configurations of small volume boilers were studied. I wanted a generator of a type that was inherently stable without the necessity of cause and effect control systems. I also wanted to devise a steam generator that had the manners of time honoured volume boilers and firmly believed as I still do that this could and should be the path to follow. Records of the successes of Winslow boilers and their derivatives the Derr boilers brought me to favour these types for replacement. Time and circumstances caught up with me and I terminated my workshop activities to give fulltime care to my then ailing wife. Now since 2005 my steam interests and fellowship with steam buffs and my third generation younger families fill my daily life.

A fellow enthusiast who owns a museum in Northland bought the little steam jeep and keeps it among his display pieces. So that leaves me enjoying being a nonagenarian pounding out on my computer themes and schemes and things the way they were and possibly could have been. I hope to discuss some of these meanderings in future instalments.

Sunday, July 4, 2010

MINI STEAM JEEP (STEMKA) 1




The steam-powered mini-jeep here described was not intended to be a contribution to the cause of motoring. It was the realisation of a desire to produce a steam-powered vehicle that gave a riding experience to its driver and passenger with freedom from the constraints of an earlier 7¼-inch gauge railway. The design was based on the American army jeep. No accessories requiring other installed power were included.

The actual construction time was 2050 hours spread over 5 years from 1987 to 1992. The total cost of materials and purchased trade components came to 2050 dollars, by coincidence a dollar spent for each hour of productive work. Double the workshop time was spent on scheming, planning and drawing. It was a labour of love, my idea of leisure and pleasure. Following the preliminary design work a wood and cardboard scale model was made and construction commenced with the details being determined as the project advanced. The objective was to create a fun machine relying on solid fuel firing, and not aimed at highway travel or commercial operations.

The flash type steam generator consisted of 65 feet of ¼” nominal bore steam pipe formed into a stack of ten zigzag grid elements located in the combustion gas flue of a wood burning furnace. The heating surface area was 9.2 square feet and the fluid content was 1.1 litres. The maximum working pressure was 600 pounds per square inch. The furnace volume was 1 cubic foot. The engine was a duplex open frame type with twin double acting cylinders of 1 5/8” bore X 2” piston stroke. The ¾” diameter X 7/8” travel piston valves were actuated by the Marshall variant of Hackworth valve gear that provided for expansive working and reverse. The 1 to 2½ ratio chain drive from crankshaft to differential gave an engine speed of 1100 RPM at 40 KPH on 16” diameter road wheels.

At start-up the wood chip fire was established and some water was pumped into the boiler by a few strokes of the foot pedal operated feed-water pump. Steam immediately generated and was blown through the engine to warm up. As pressure increased the car literally chuffed off. When the vehicle was running the boiler feed-water supply was taken over by the rear axle driven feed pump. 100 PSI was sufficient to motor on flat road.

It is important that boiler feed-water supply is matched as closely as possible to the steam demands of the engine. Ideally such control should be completely automatic but it was difficult to achieve a balance in this application because of the inexact practice of hand firing solid fuels plus the wide variations in demand on the road motoring. Various patterns of boiler pressure actuated feed-water control valves were made and fitted before being abandoned in favour of a manually controlled water metering and bypass valve that returned acceptable results providing that the driver remained alert to the cause and effect performance signals. The state of the steam generator was judged from the pressure gauge, the feel of the throttle and engine responses and the forces required on the priming pump pedal. With all of this in mind the furnace conditions had to be sustained by the frequent addition of wood blocks or pine-cones. Fuel consumption worked out at eight to ten pine-cones per kilometre. It was true seat-of-the-pants motoring.

The forty litres of feed water carried served about 2 hours of start/stop motoring around local streets, grassed recreation fields or on hard sand flats of the local tidal estuary. The car was driven on the hand or foot-operated throttle with high boiler pressure, or with minimal boiler pressure and the throttle full open with the speed controlled by the regulation of feed water delivered to the boiler. My wife and I once drove the car by this method in a town festival street procession. She was the fire attendant.

Monday, June 14, 2010

7¼ INCH GAUGE STEAM LOCOMOTIVE




Interest in steam engineering had never lingered far beneath the surface of my dreams. Things that breathed steam and the engineer’s lathe together with the odours of cylinder oil and cutting oils were as flavour enhances to good foods. The urge to build a 7¼-inch gauge steam locomotive with riding trucks and portable track converted to action and by 1961 became operational hardware that over six years enlivened social functions. The locomotive was loosely based upon a New Zealand Railways Baldwin built 4-6-0 tender engine. The chosen track gauge being close to one sixth that of our NZR standard 3’-6” became the scale for the model. The object of the project was to create a small locomotive displaying the character of a full-size engine. The necessity for portability by car trailer limited the amount of rail track that could be carried which on completion came to 210 feet (64m) consisting of thirty 7-ft (2.134m) lengths that laid out in an oval comfortably fitted around my house. The radius of the end curves was too tight to accommodate a sixth scale 4-6-0 locomotive so the design was modified to a 2-4-0 yielding the flexibility of a four-coupled engine. The leading axle was mounted in a swivelling pony truck. While the engine was built to free-lance concepts its visual features were to scale proportions. The boiler was of locomotive pattern formed from 3/16 inch (5mm) steel plate with copper fire tubes and super heater flues. The cylinders were 2¼ inches (57mm) bore by 3 inches (76mm) piston stroke with 1 inch (25.4mm) diameter by 1 1/8-inch (28.575mm) travel piston valves and the driving wheels were 7 inches (178mm) diameter. The fire grate measured 9 inches (229mm) by 4 inches (102mm). Fuel was kerosene fed by a steam atomising scent spray type burner aimed through an aperture below the normal fire door. Carbonettes were used to stabilise the fire. Boiler feed-water was by axle driven pump while travelling and injector while standing. The tender rode on two bogies and carried 8 gallons (36 litres) of water and 3 gallons (14 litres) of kerosene as well as providing the riding truck for the driver. The engine and tender empty weighed 563 pounds (255kgs) of which the engine accounted for 391 pounds (177kgs) with 317 pounds (144kgs) on the driving wheels and 74 pounds (33kgs) on the leading pony truck. The driving axle suspension was compensated so that axle weight distribution was not affected by track irregularities.

There were two 7 feet (2.13 metre) long riding trucks each weighing 196 pounds (89kgs) carried on bogies. The seating was central plank with footboards. Each length of track weighed 41 pounds. (18.5kgs). the colour scheme was hawthorn green boiler, cab and tender. The smoke-box, chimney and under frames were painted black and the headstocks red. The passenger trucks were grey seat boards and footboards with red side panels.

Raising steam from cold was achieved with a wood chip fire with draft induced by a hand-cranked extractor fan fitted on the chimney. After a few minutes when steam pressure showed 2 pounds per sq. inch the chimney fan was removed and the blower and kerosene burner were opened up. 12 minutes from light up was the normal time required to attain the working pressure of 90 PSI. When first placed in service the ability of the boiler to maintain full pressure on load was fairly poor and much heat was wasted in the smoke-box which scorched the smoke-box and chimney paint. This was rectified by fitting a feed-water-heating coil of copper tube around the inside of the smoke-box. The engine then became a very free steamer. Even under full load the boiler easily gained water level and steam pressure. The burner steam and fuel jets had long tapered needle valves that allowed fine adjustments and produced smoke-free combustion.

Monday, May 31, 2010

RETURN TO ENGINEERING 2




While engaged with the firm I did make a contribution that prolonged its dying agonies for another four years. The agricultural bulk fertilizer spreaders of the times carried five tons on a truck mounted hopper and hauled five tons on a trailer fitted with a V section hopper with a top mounted chain scraper and chute that was supposed to transfer its load to refill the spreader hopper. The process was extremely slow with dry fertilizers and failed completely if the materials were damp or wet. The operators were forced to hand shovel the loads across. My solution was to utilize a proven spreader hopper with its travelling mat floor. The idea was to elevate the rear end of the hopper by means of a tipping truck hydraulic hoist and a radius linkage between the hopper and a standard trailer chassis. This brought the discharge end over the truck hopper when the travelling floor mechanism was engaged and the load transferred in three or four minutes. Success was immediate and about four hundred units were constructed and distributed throughout New Zealand, Tasmania and a few to Victoria and South Australia. Indeed the concept became adapted to some field crop harvesting and provided a feeder appendage to packing house sorting benches. In fact load in the field and self discharge at delivery. My reward was, “go to it and make them faster”.

After four years in this rough and tumble I went into the trades teaching section of a secondary school and stayed for five years achieving nothing worth recording and failing completely to appreciate the politics of the system. I then joined an intermediate school to establish and teach in its new metal crafts workshop. I actually enjoyed the experience for a few years creating a break-away from the traditional forged poker and boot scraper approach. I guided the introduction of forms 1 and 2 girls to metal crafts when all boys and girls were initiated to the four craft subjects. The old time-worn idea of weeks to produce a work of art in metal craft was thrown out and indeed we produced a simple item the first day of the student’s contact. I stayed twelve years and for three years was senior and visiting teacher in the subject for the district education board of the time. I was approaching age 58 and resigned and gave myself three months holiday.

I enjoyed the liberty then without too much sense of compulsion went looking for a job, mainly part time employment. I landed three engineering orientated jobs and accepted one in a nylon yarns processing factory. I stayed there for four years as purchasing and personel officer. On the way I was able to resolve a few engineering problems, find sources of machine component supplies and fit staff to jobs and jobs to staff.

At age 62 I walked into my office one morning and noted the four walls just all too close so decided to call it a day and gave a months notice and happily walked away from paid employment. Then I really started work, that is work in my home workshop that I really did enjoy. A little money to cover costs, some barter and creative satisfaction. The pottery crafts people wanted pottery wheels, associated accessories and kiln oil burners all tidy work within my capacity. The wool spinners and weavers wanted wooden bobbins, needles, loom components, buttons and toggles. This was delightful work with added pleasures of the aromas of the various woods. This too called for the scheming out and making up of single purpose machines to facilitate production. But I get ahead of the story. Back in my school teaching days I had my home workshop up and running and I was preoccupied with getting a life and practicing engineering in the way I wanted to. There were interesting things to be done and it was time to get going.

Sunday, May 16, 2010

RETURN TO ENGINEERING 1




I re-entered the engineering trade in 1944 in a works catering mainly to the agricultural industry. The war still had two years to run and imports were severely restricted. The existing fleet of pre-war farm tractors needed constant maintenance and repairs. By 1946 when the first of the British built Fergusson and David Brown tractors started to appear versatile workshop technicians came into their own. The Fergussons were a success from day one but the David Browns showed a propensity for shattering their differential gear carriers and it fell to me to fabricate and machine new replacements. The first models had no provision for front end attachments such as high lift platforms, loader buckets or grader blades so an exercise handed to me was to find a way to accommodate these essential attributes. With this resolved many David Browns that would not otherwise have left the show room were sold. Sales of new tractors meant that well used American tractors such as Internationals and Fordsons were traded in. Parts were difficult to obtain so many bits and pieces including sets of pistons were machined from locally produced castings. Also onto the market came a flood of imported powered row-crop cultivators for market gardeners. These presented an opportunity to scheme out and make up sets of high pressure spraying equipment that could be fitted or dismounted as required thus increasing the versatility of the machines.

As the war drew to an end some ex-service men with agricultural backgrounds chose to pick up rehabilitation business loans and set up as earth moving contractors. They purchased mainly second hand Caterpillar and International crawler tractors and had them overhauled and fitted with bull-dozer equipment. In those times winch operation was becoming outmoded and hydraulic actuation was taking over. Sets of this equipment were not imported so had to be locally manufactured to fit each application. I had a keen interest in this work and over five years made up many sets of hydraulic rams, control valves, pressure relief valves and gear pumps. I was head-hunted and offered a remuneration inducement to work for an automotive engine reconditioning firm. My first year’s wages for the same hours went up by 60%. My main work was operating a newly installed crankshaft journal regrinding machine as well as being given experience on cylinder reboring, piston finishing, engine block main bearing line boring, connecting rod bearing machining and fitting. Sandwiched among this was making engine components for vintage and veteran automobiles. The design and production of specialised single purpose machine tools to facilitate refurbishing of components was another sideline. On the way I added a trade certificate in automotive machining to my engineering turning and fitting certificate.

In answer to a job advertisement for a works foreman for a road transport equipment manufacturing company I took up employment that turned out to be totally out of my tree. Management’s appreciation of engineering was seeing sparks flying from electric welders and portable grinders. The firm was under equipped and under financed with disillusioned share-holders withdrawing. On my appointment I was charged with the task of guiding the works to manufacture freight trailer chasses as fast as possible. The managing director and his sales team would match the output. So after two months there were trailer chasses stacked to the roof and few sales contracts. Stop, stop went up the cry and we catered more and more for repair work that held no interest for me.

Wednesday, April 28, 2010

STEAM AT WAR 13




We put into Freemantle for thirtysix hours and had twelve hours shore leave. Most of the troops went into Perth to spend the time. A few of us teamed up, had dinner in Perth and took an afternoon train a little further inland to Midlands Junction where the Western Australian Railway workshops were located. We were welcomed and given a tour of the works and shown new locomotives for their railways and boilers under construction for mine sweepers. We were treated to a few social beers in the local pub and returned on the worker's train to Perth and Freemantle.

Next morning the convoy set off down the coast round the corner and across the Australian Bight and in a few days put into Hobart. We passed in through the submarine barrier that consisted of heavy steel netting at the sea end of the deep entrance bay and drawn aside by mine sweepers to make passage. A destroyer followed the ships through dropping depth charges prior to the closing of the barrier. We sailed up that scenic tree and farmlands bordered waterway to the town backed by snow-capped Mount Wellington. We were there for six frustrating hours with no shore leave and again set off across the Tasman for good old New Zealand. We passed south of Stewart Island and up the South Island east coast with the Dunedin contingent recognising the Otago Peninsular. It was a murky day so did not see any more land until arriving in Wellington Harbour on the morning of 12th of July 1943 to the overwhelming pungent odours of lush bush and ferns.

The Wellington and Hutt Valley troops were disembarked within a few hours of berthing followed later in the day by the Auckland and South Island people. The Manawatu, Wanganui, Taranaki and Hawkes Bay troops were off-loaded the next day. Adjacent to our quarters was a ships orderly room containing an extensive range of office equipment including thirty Remington typewriters. On the morning after our arrival only twenty-nine remained. What a witch hunt took place! But they were looking at the wrong people. No doubt someone's rehabilitation in the secretarial world got off to a good start. Those like myself bound for Palmerston North were disembarked in the early afternoon and within three hours reunited with our families.

The New Zealand Railways due to wartime pressures were very short of staff which was the main reason why the government wanted the railway battalions back home rather than being sent to another theatre of war. Thus, the companies were disbanded and the men returned to their jobs. I was retained in the army for three months while undergoing hospital treatment for my now very severe digestive disorder. The retention of food was an ongoing problem. Finally I was discharged on a war pension and unofficially warned that if I valued my pension not to take up any employment. At age 24 this was not news to my liking. I went back to work where I had left off as a locomotive fireman that did nothing for my health. The irregular hours of work, sleep and meals took its toll so after seven months I resigned from the railway and re-entered my first choice of trade as a turner and fitter in a small engineering works serving the district's agricultural industry and lost my pension. With the support of the returned servicemen's rehabilitation scheme I completed my engineering apprenticeship and gained trade certification.

I recovered my health, married my wartime correspondent and used my rehabilitation loan to build our home. We raised two daughters, moved on in my trade to leading hand, works foreman, works manager, secondary school teacher in technical subjects, middle management in a textile factory then retirement but not idleness.

Saturday, April 17, 2010

STEAM AT WAR 12




As the active war zone receded westwards and the North African ports became operable the desert railway ran out of work as a supply line but continued in use bringing out the vast quantity of war wreckage. Our 16th operating company was relieved from what had been a long and arduous term of duty, and withdrawn to the New Zealand forces base camp at Maadi.

I was joined to a small detachment of eight men to be transported to El Kantara on the Suez Canal to pick up a fleet of diesel electric locomotives and ferry them up to Beirut in Lebanon. There we were to establish train-loading schedules over the routes from Beirut to Haifa in Palestine and Beirut to Tripoli in north Lebanon near the border with Syria. We also had to train South African engine-men to operate the new diesels that were displacing steam engines that in turn were being sent to work in Turkey.

We were based in a beautiful campsite in an olive grove with fourteen American technicians who maintained the locomotives and sixteen South African engine-men. There was excellent comradeship among this specialised group and life was idyllic. The north and south runs were right on the Mediterranean coast and we were given the superfluous advice to not permit night-time lighting that could be visible from the sea.

After four months in this beautiful part of the world the four married men of our group were recalled to base to prepare for furlough to NZ. We held a farewell party and gave those who lived near our homes messages to our families. We remaining single fellows carried on in apparent isolation but we were not forgotten and a week later in some urgency we were commanded to return to the furlough embarkation camp at Giza in the shadow of the Great Pyramids. Thus, after a four-day train journey we arrived and divested ourselves of everything that we could not carry in our sea kit bags. Four days later we were transported by road to Suez, loaded onto the 37000 ton New Amsterdam and at 16.00 hours that day weighed anchor and commenced the thirty day homeward journey. There were more than 6000 troops aboard. We enjoyed three meals daily and those of us who gained possession of one of the 700 library books read the time away. A few of them were good and some utter rubbish, but the possession of a book meant that one exchanged it hand to hand for another. There were frequent appeals for the return of all books to the library under threat of cessation of further issues. As the library was empty we did not fall for that one. They got them back at the end of the voyage. We were billeted up on an enclosed weather deck in rather more comfortable conditions than we had experienced on the outward journey nearly three years earlier. We actually enjoyed reacquainting ourselves with hammocks. After two days sailing down the Red Sea we put into the port of Aden and lay at anchor for two days within the perimeter of volcanic peaks surrounding the huge crater harbour. We were not ashore and by the look of Aden with its barren surrounds we did not feel deprived. Our ship was joined by thee more to make up a convoy that changed in structure at various points of the journey.

We departed Aden and steamed across the Indian Ocean to pass off Colombo and head down the Australian West Coast. By day the convoy travelled at moderate speed pursuing a zigzag course and at night speed was increased and a straight course followed. The Dominion Monarch was stationed off our port beam. In some heavy weather we were to see her plough through waves cresting higher than her bridge superstructure. Frequently our escorting destroyers and light cruisers would turn off and disappear over the horizon and hours later or next morning were back in their normal stations. When we reached the Australian coast the warships went off elsewhere and Catalina amphibian aircraft took over the escort duties. We noted members of the crews visible in their observation blisters.