Extracts from the National Steam Centre Newsletter

Issue 566 March 2018 Worth £ 3/0/0

Also in this Issue

Rally Preperation Inertia Engine Starters Waterous Spark Arrester

Above Ross, Warwick and Bill admiring the just installed Lucknow steam compressor donated by the Lloyds Jo Lloyd photo

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INERTIA STARTERS People seem fascinated with the starting rigmarole involved with the Inertia starter of the Large Guiberson Diesel radial engine down at the Steam museum . Here is how it works ! Background Actually the standard staring equipment for the Guiberson Diesel engine is a Breeze Corp “Cartridge Engine Starter” but not having a breach block or cartridges an alternative has to be employed. Fortunately an electric starter from a larger petrol radial engine came with the Guiberson.

This is quite a technical odyssey in itself as it uses the energy built up in a very small very fast spinning flywheel to start the engine . Why This avoids the high currents required with direct electric cranking. By building up the energy over a minute or so with a small electric motor the weight penalty associated heavy batteries and cables required to do the same job over just a second or 2 are avoided. The trade off is the time it takes to start the

engine and if it does not

start the whole process has to be gone through again . Under conditions of war any delay could spell disaster so direct cranking systems were adopted and the weight penalty avoided by powering the starters from a portable jumper lead and battery pack which was left behind on the ground on takeoff. Construction After being repeatedly asked how the inertia starter worked curiosity got the better of me and I thought I had better have a look inside to see just how it worked as it was not obvious from the outside. In fact all that could be seen was a heavy and a light electrical connection and as small lever that seemed to cause the driving dog to engage and something missing on the end. Actually being of aircraft origin the starter does not use a pinion and ring gear since these engines do not use a flywheel but engages directly with a dog on the end of the crankshaft

Above Inertia starter motor on Guiberson radial Diesel acts directly on the end of the crankshaft

Above Jack & Heintz 24 volt Inertia Starter Motor

Above Retractable Heavy duty 12 tooth ratchet dog engages directly with the crankshaft

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Flywheel First I pulled the electric motor end off which revealed the flywheel. It is steel about 140 mm in dia with a 50 mm wide by 10 mm thick rim mounted on a disc hub directly attached to the electric motor armature all this spins on a pair of ball bearings. See Right Photo The Motor is unusual in that although it has a hefty commutator no windings are visible they must be in passage ways rather than slots to resist being thrown out by centrifugal force indicating that high revs are involved .

The fields are also unusual as they have interpoles , features usually employed to resist the distortion of the magnets flux at high rpm to minimize brush sparking. Internal connections suggest a series motor which have the characteristics of a higher than normal speed on light load and strong starting effort . The high speed occurs because the faster the armature spins the more the motor acts as a generator with the result that this back voltage opposes the current so the field magnetism is

reduced allowing the motor to spin even faster. According to an old book “ Direct Current Instrument , Generators and Motors ICS 1923 “ the

no load speed of a series motor can often become dangerously high and the rotating parts burst by centrifugal force . See chart to the Right So with all this precautions exactly what is the speed ? Controls with no sign of a switch or solenoid , the only control is a small lever on the end of the motor. Activating this raises the brushes off the commutator and extends the starter dog to engage with the engine crankshaft . Releasing the lever retracts the dog while the brushes stay latched up until released by a small

solenoid. Reduction Gearing A small helical gear on the back of the flywheel feeds into a double reduction gear train which in turn drives a double planetary gears system with each gear set being heavier than the preceding one since the torque goes up in proportion to the reduction in speed .Curiosity meant the overall ratio had to be known so the number of turns of the motor was counted to give one turn of the output

shaft , this seemed easier than counting teeth and doing sums. The answer was just over 300 . This makes sense as the over all reduction is the individual ratios multiplied together each stage would have to give a reduction in the order of 7 to 1 .

So How Fast does it Spin . I knew it was going to be faster than any tacho I had but thought it might be possible to time the output shaft so it was set up on the back lawn and connected to 2 , 12 volt batteries and switched on .

Above Field interpoles allow operation over wide speed range .

Above Hooks to lift the brushes Motor is switched on or off by a mechanism that lifts the brushes .

Right Reduction is in 4 stages using epicyclic and spur gears.

Above Accelerating electric motor and flywheel

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Once the flywheel was spinning as fast as it was going to get to and a bit of help with counting and a stop watch was enlisted ( actually my daughter and her an I phone ),. It did 26 ½ turns in 15 seconds which makes 106 rpm . A bit more maths showed the flywheel was spinning at an incredible

31,800 rpm .

Right The timing experiment set up on the back lawn

How does such a tiny Flywheel turn a 17 litre Diesel engine. It is all to do with the kinetic energy ( the energy of motion ) stored in the flywheel . It is a function of velocity squared so if you double the revs of a flywheel it has 4 times the energy. With our 300 times the speed we have 90,000 times the energy ( capacity to perform work ) i.e. crank the engine. In other words the engine will think it is being started by a flywheel 90,000 times bigger than it really is. Off course you do not get some thing for nothing as the battery still has to supply the same amount of energy overall as for direct starting but instead of a lot for a moment it is a smaller amount for a longer time as the flywheel is accelerated up. This allows proportinately smaller batteries , cables and electric motor whith the associated weight saving. Starting Procedure Some people think this is the best part of the performance and crowd around not to miss anything. It goes something like this :- - Bar the engine over on decompression by hand , at least 3 turns, to clear the cylinders of any oil - Touch the start button . This activates a small solenoid that drops the brushes onto the commutator and the electric motor starts to spin up the flywheel . - Wait for flywheel to reach maximum speed easily determined from the pitch of the noise . - Throw the lever across which turns the motor off by lifting the brushes and engages the starter dog. The starter then proceeds to rotate the engine as the torque limiting clutch takes up . - Motor over on decompression till the engine turns smoothly. - Slam engine speed control to full fuel . BAM— ROAR Those too close jump back and put their fingers in their ears while getting splattered with oil and covered in smoke. A Great Performance !

Keep your eyes out and ears open to be sure you do not miss the starting demonstrations of the Guiberson radial Diesel engine at the rally .

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The very distinctive bulbous spark arrester is a defining feature of Waterous “Fire Proof Champion” steam engines. Unfortunately the one on Jo Lloyd’s recently acquired portable engine had been damaged so considerable research was put into understanding how it worked followed by exploring options for it’s repair . How it was intended to work was a mystery so it was off to Google to try and find the answer. Google research showed that the spark arrester was originally patented by Waterous’s brother-in-law David June who subsequently assigned the rights to Waterous. A search of the patents turned up an explanatory diagram. Right The bulbous base of the spark arrestor is filled with several centimetres of water. The flue gasses come up from the boiler and are deflected down over the water then up through a pair of slotted screens before exhausting through the flue. The idea is that as the gasses swirl through this labyrinth any particles will drop out and fall into the water. The fallen cinders wash out through an overflow when more water is pumped into the bowl.

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Waterous portables had their main original market driving threshers on the prairies and reducing the fire risk was a strong selling point. They sold over 2500 of these engines over a couple of decades so the system must have convinced the market. Right Promotional material for the Waterous engine see Jo Lloyd’s article Steam Supreme 560 Sept 2017 The Lloyds engine spark arrestor had suffered a lot of damage. It looked as if it had hit something while being towed. The bulb shaped casting, probably embrittled by being worn down by the passage of the hot flue gasses, had shattered.

Most of the broken pieces were found sitting on the upper tube plate.

Below Enough remained to give a pattern maker all the detail he needed to reproduce it.

A foundry in Ballarat was prepared to take on the job and it is currently at the pattern makers and should be recast shortly. ( just before the rally )

Below The upper part of the flue is rolled and riveted sheet steel and should relatively easily be remade.

I hear a whisper the Waterous will be displayed in an advanced state of restoration complete with the spark arrester although not yet in steam for the rally. Below The engine as acquired

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Rally Layout Below is the layout of the rally field and a few things to keep in mind . Use this as a guide when setting up your displays or directing visitors. For safety all displays must be set up before gates open to public. To create a heritage atmosphere limit fluoro clothing to designated officials and have all modern cars off the site and in Exhibitors park by 10 am . The path for the Tractor Trek ( and other mobile exhibits) is shown , be in place and move off at scheduled times , do not wait to be asked. Finally remember to sign in and pick up your name tag from new sign in desk when you arrive.

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MeCALAC Mechanical Marvel Aaron Morris has specially brought his Mecalac digger down to the MSTEC grounds to assist in getting things in order for our rally. This French developed machine has a very sophisticated hydraulic system that allows it to virtually mimic the actions of the human hand including grasping , wrist and elbow actions in addition to the usual raising and extending of conventional diggers , making it extremely versatile in what it can do. On the weekend he had it in action all over our grounds first out in our carpark levelling and filling in pot holes made by heavy trucks using it as an unofficial rest area. Next it was over to shed 7 pulling up roots of the old cactus , levelling the ground then spreading gravel to create a safe arena walkway for the rally visitors . Other jobs included helping with the backfilling of the Willans foundation and cleaning up around the stone crusher. Take time to have a look at the machine I expect it will be demonstrated at the rally , we are so lucky to have the services of this type of equipment—for free ! Smart New Sign In desk It is funny how when you see something everyday you soon stop noticing it . This was very much the case with our sign-in desk just inside bay 1 pedestrian door. We took it for granted but visitors were apt to see a lop sided decrepit old table. Not a good first impression for our museum. Well that has all changed Warwick eventually noticed it and added it to Ray Bedford's Maintenance List and before we knew it Adrian Anderson and Brian Wright were soon beavering away installing a smart new cantilevered replacement . I am sure you will be impressed with it when you come to pick up your name tag for the rally

Below The new first impression . What a difference a bit of thought and a couple of hours work can make . Lets see what we can do when we get Bay 0 underway ?

Mind the Yellow Box ! Another simple job around the club that can be ticked off thanks to Nick and Geoff Lintoff is the painting of yellow warning stripes over the level crossing at our front gate. First time visitors to our Steam Museum may be surprised to be confronted by a small train as they come through the front gate especially during the rally as we anticipate train rides will be quite busy . The brightly painted yellow rectangle with diagonal stripes will certainly catch their attention . Use them as a prompt to look to the right for trains as you enter the Museum grounds .

This months Around the Club features very much the efforts being put in by members to prepare for our big 50 th Rally . Above Aaron Morris levelling the arena walkway in front of shed 7 .

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Willans Update At the time of writing the foundation is ready for the final pour with the reinforcing all in , formwork completed and the perimeter backfilled thanks to a huge effort by a number of members.

The committee sees it as very important that the concrete be in and the engine base in place as a significant landmark in the club's history for the 50 th rally after all it is 46 years since the preservation of this engine was first mooted. For a while it looked like this was unachievable despite Bill and Warwick working 22 days out of the last 26 many of them long hours. Thanks to the overwhelming response by so many club members to appeals for help we are now ready for the concrete . Drop in at the rally as see if we made it Steam Train for the Rally Despite Our Franklyn Flyer being laid up with boiler problems it looks like we will have steam train rides at the rally thanks to Phillip Hayes following successful trials with his steam loco on our track last week end. The origins of Philip’s loco are a bit obscure but it may have been the one that ran at the Zoo in the early 1950’s .It is rather a distinctive little loco with cylinders off a steam car and square boiler casing containing a water tube boiler. If anyone has photos of

the Zoo train bring them to the rally and show Phillip as it may solve the mystery. Below Ray Bedford and Ken McLeod observe trials of Philip’s engine double heading with Barry George on Joy with 3 carriages.

Below closer view of Phillips distinctive engine now fitted with wider tyres to the driving wheels to adapt it from 11 1/2 “ to 12 “ gauge.

Above Nick and Geoff lining out the crossing . With any luck we will have lights as well by the rally.

It’s Beak can Hold more than it’s Belly can

Below The Morris “ Pelican “ removing weeds from the lake in preperation for the Rally steam boat .

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After a very special effort we completed the concrete and got the engine loosely installed just hours before the rally Stop Press

(Just for Wisp) Readers

Above The last kibble load of concrete going in , the concrete blocks are to stop boxing floating Above The 6 tonne base bedplate fits perfectly

Below It is only when the cylinders go on does the massive size of our Willans Air Blast Diesel become apparent.