Squib 2

[gary smithParticipant @garysmith96394]

I have recently aquired a flash steam straight runner named "Squib 2" from my late father. I believe it may be somewhere near 80 years old. I have known this model for many years, having met the original builder and designer, A.L. (Len) Gates, A friend of my fathers for many years. I managed to track down the model through my cousin and keen modeller Mike Smith in Gt. Yarmouth. Much of the boat is now missing, Including the alloy coach roof, boiler and blowlamp, however the hull and deck is in quite good condition, being I believe of tinplate and the engine appears complete lacking it seems only its oil tank. The twin screws and related gearing appear to be perfect.She came with an article in laminated plastic, pages I believe to be either from "Model Boats" or "Model Engineer". This is quite informative, showing Lens drawings of the boiler, which I would like to build, and two pictures of Squib in action, one with the late Mr. Gates operating the vessel. I would very much like to restore the boat to the condition I remember as a boy, having seen her run on a few occasions with the Victoria Model Steamboat club, and in later years with the Mayesbrook model power boat club. Here though is the problem….My experience of steam models is limited to a "Mamod" single cylinder occilating stationary engine some 35 years ago, and to my vague memories of Squib from around the same time! I shall be attempting to fabricate a boiler from Lens drawings, but if anyone could give me any advice I would be very grateful. I am a diesel engineer by trade with workshop facilities so am quite capable, but I am of a generation which sees flash steam power as somewhere close to alchemy! In all truth I understand double and triple expansion theories but really am not sure how a flash steamer works. I would love to hear squib run again as the sound was indescribable, a kind of whirring howl. Are there any modellers out there that remember this boat or any similar? If there is much interest I will post photographs, and the original article, if copyrite permits.

[Paul TParticipant @pault84577]

Hi Gary

Try looking at http://www.flashsteam.com this is a site dedicated to The Flash Steam Engine Experimenter and contains some very useful information.

The Kingsbury Park model boat club also have a page dedicated to flash steam this can be found on  http://www.kwpmbc.co.uk/tetheredhydro.php

And there is a very informative page at http://www.onthewire.co.uk/hhistory.htm giving the history of flash steam over the past 100 years.

I am very intrested in steam but have never used a flash steam engine and would be very glad to see some photos of your late fathers boat.

All the best

Paul

[gary smithParticipant @garysmith96394]

 Thanks for response Paul, Will post pics and progress reports asap.  trying to find space to work at the moment. I got Squib at home, she’s 50 inches long and my shed is 6′ x 4′ and stacked with motorcycle parts and another boat! you probably familiar with that scenario I take it! Thanks for the links

all the best

Gary.                                                                                                                                                                

[Paul TParticipant @pault84577]

Sounds just like my shed only mine is 15 x 6 and full of power tool and boats, so much so that I have had to buy another shed to keep the completed boats in….and I still can’t get to my bench.

Cheers

Paul

[gary smithParticipant @garysmith96394]

 Sorry about the delay with Squibb 2 " pictures. computer prob and lack of time. Will rectify asap.

[Paul TParticipant @pault84577]

No worries Gary

We all have busy lives and posting photos will come a long way down on anybodies list, it will be nice to see them when you have the time.

Take care

Paul

[ashley needhamParticipant @ashleyneedham69188]

Gary. I have looked at the links as suggested, but I think there may be some confusion, and no doubt i will be corrected if not right, as to what bit on your boat is "flash". I suspect that you mean a flash steam generator..ie a boiler working on the "instant steam" principle..these are, I gather. able to produce steam and lots of it very quickly, ideal for a fast boat. A flash steam engine works on the principle almost of a deisel engine whereby steam is only generated in the actual cylinder, just like the explosion of petrol or diesel (yes I know in theory it is just burning very fast). This sort of engine, as far as my quick perusal goes, appears NOT to need a blowlamp? It looks like this sort of engine is a bit complicated, and perhaps too much so for a model boat…but the boiler is a different matter. A "pop-pop" boat is in theory a flash steam generator….    Or do i have the wrong end of the jolly preverbial stick? .Ashley

[Paul TParticipant @pault84577]

Gary

The following should fully explain what Flash Steam engines are and how they work, sorry that is so long winded but it is very accurate.

The phenomenon of ‘flash-steam‘ is well known to engineers and its application to the steam engine offers a route to significant improvements in steam generating efficiency.

Water if pressurized remains in the liquid phase at higher temperatures and does not boil and vaporize. If such pressurized and heated water is released through an orifice to a lower pressure, part of the water immediately and explosively turns to steam – a process known as ‘flashing’. Flash steam is currently exploited in applications such as geothermal power plants. In these, water is drawn from deep underground where it is at high temperature and pressure. Piped to the surface, this water is ‘flashed’ in a chamber to produce steam under pressure which is then expanded in a more or less conventional turbine coupled to an alternator to produce electricity.

Flash steam, therefore, offers one novel way of making a modern steam engine. In Section – 3 the mono-tube steam generator was described. This was the type of steam generator favored in the last production steam cars and was often found in stationary or ship steam plants. This type is almost always employed in current experimental steam vehicles. In the flash-steam generator, however, the idea of the mono-tube steam generator is taken one step further.

The crucial difference between these two types of steam generator is that, as previously explained, the mono-tube generator raises steam within a coiled tube which contains water of increasing temperature in the first section, saturated steam in the next section and superheated steam in the final section. Steam is admitted to the engine cylinder by means of a valve. In the flash steam generator, however, the coiled tube contains water only. The coil is heated in a similar way to that in the mono-tube generator, the difference being that the water is pressurized to a level above its saturation temperature and is injected into the engine cylinder as water.

cont:

[Paul TParticipant @pault84577]

The following table is an extract from standard steam tables and shows that, for example, the saturation temperature of water at 10 000 kPa is 584ºK. Therefore providing the pressure is always maintained above 10 000 kPa, the water in the coil always remains in the liquid phase and does not turn to steam.

EXTRACT FROM STEAM TABLES

Pressure kPa1005001000500010 00020 000Temperature ºK372425453537584639

As there is now no steam in the coil, the steam inlet valve is replaced by an injector which admits the pressurized high temperature water directly into the engine cylinder. Employing an injector to deliver liquid rather than admitting steam through an inlet valve is of considerable practical advantage. Firstly the quantity of water injected at each stroke is far smaller than the volume of steam passing the inlet valve in an engine served by a mono-tube generator (steam at atmospheric pressure occupies about 1650 times the volume of water). This tiny quantity of water is simply much easier to dispense through an injector than the much larger volume of steam which an inlet valve must admit in a mono-tube engine. This bestows a secondary advantage – namely speed. Such a small quantity of water may be dispensed at speeds equal to those found in diesel injection systems, whereas steam which has to negotiate an inlet valve is seriously impeded if the engine is pushed to higher speeds by a phenomenon known to steam engineers as ‘wire-drawing’.

As the pressure in the engine cylinder is always much lower than the saturation pressure of the water in the coil, once it is injected there is no possibility for the water to remain in the liquid phase and part of it ‘flashes’ into steam. The flashing process results in ‘wet steam’ because only part of the water is converted to steam whilst the rest is atomized by the flashing process into tiny droplets of water. The proportion of water converted to steam is obtained by subtracting the internal energy of the water at the lower pressure from that at the higher pressure. It may be calculated from the equation:
Uf P1 – Uf P2 x 100 = % Flash Steam
      hfg

Where:
Uf P1 = Internal energy of water at higher pressure (kJ/kg)
Uf P2 = Internal energy of water at lower pressure (kJ/kg)
h fg = Enthalpy of evaporation (kJ/kg)

Applying this equation to circumstances where the water is pressurized to above 20 000 kPa which allows it to be heated to 639ºK gives the following result:

1786.9 – 417.86 x 100 = 60.6% Flash steam
      2257.6

cont:

[Paul TParticipant @pault84577]

Therefore under the above conditions 60 percent of the injected mass of water is immediately converted to steam in the cylinder but 40% remains as water which is atomized into very tiny droplets by a double mechanism. The first mechanism is a result of the depressurization of the liquid water through the nozzle in much the same way as can be found in industrial liquid- spraying systems. The second mechanism results from the explosion of the flash process itself. The two mechanisms occur simultaneously and support each other during the time that injection of the water takes place. This very effective atomization is crucial to the next phase of the expansion process in the cylinder.

If the water were to be injected into a cold engine cylinder, the flash steam would immediately condense and there would be no pressure rise. To overcome this problem, the cylinder head and walls are heated and supply additional heat to the wet steam entering the cylinder. The atomized water droplets experience extremely high collision rates with the cylinder walls because of the explosive effect of the flash process. The tiny size of the droplets, coupled with high collision rates ensure rapid absorption of heat allowing them to be quickly converted to steam which is then heated further to superheat.

A flash steam generator permits the construction of a steam generating unit which is much more compact and has fewer thermal losses than a traditional steam boiler.

N.B. Monotube steam generators are sometimes confusingly referred to as flash-boilers or flash- steam generators. However the key difference between the monotube generator and the flash generator is that in the former water and steam exist within the heating tube, in the latter only water exists there until it is ‘flashed’ to a lower pressure through a valve or injector.

cont:

[Paul TParticipant @pault84577]

This is a flash steam system, model boats powered by such engines are capable of very high speeds

Paul

[ashley needhamParticipant @ashleyneedham69188]

Gary, A close up photographic reproduction or even a picture of your engine or remains may clear matters up….

Paul I am printing that reply to read in bed tonight !!! but was I wrong (ish) or not ? Pop-Pop engines are the closest i want to get to steam.    Ashley

[Paul TParticipant @pault84577]

Ashley

Flash steam is different from Pop Pop in a number of ways but mainly that it works under high pressure (not operating at normal air pressure) and is capable of pushing a model boat along at speeds in excess of 85mph whereas a Pop Pop is only capable of 15mph.

I fully understand your wish to only work with a Pop Pop engine as the Flash steam can be dangerous.

Paul

[ashley needhamParticipant @ashleyneedham69188]

thats why I made a rubber band boat….. hmmm  85 mph on a destroyer……where`s me drawing paper.    Ashley

[Paul TParticipant @pault84577]

Ashley

85mph that is an average figure as some flash steam hydroplanes have reached 120mph…see the site that I suggested some time ago http://www.kwpmbc.co.uk/tetheredhydro.php to see some truly amazing flash steam models.

Paul

[gary smithParticipant @garysmith96394]

Hi sorry about the delay, well, I do remember being told that squibb reached speeds of over thirty miles an hour but I dont know how that figure was decided on, but I do know she was fast. and scary to stop. I would have been about ten years old and was shanghied into being the stopper and turn arounder…well,anyway,  I was trying to turn her round, a real task as she was longer than my arm span and   wanted to be off… and all I could think about was BIG brass twin screws out of sight as i tried to shuffle my hands along the gunnels, when she decided to give me a little squirt of burning wet steam in the face….when I got my eyes open she was heading full chat across the pond! my dad was running around the edge, in chest waders, and some how got there in time….I laughed about it later but didnt dare at the time! But I will always remember the sound, whirring from the valve gear on the inline twin engine and the gearing to the twin sterntubes and contra rotating twin screws , and a kind of howl, nothing like the i/c engines I was used to. I’m going to go now and try to scan the pages from Model Engineer, and try to post some photos so wish me luck!    

[gary smithParticipant @garysmith96394]

Hi sorry about the delay, well, I do remember being told that squibb reached speeds of over thirty miles an hour but I dont know how that figure was decided on, but I do know she was fast. and scary to stop. I would have been about ten years old and was shanghied into being the stopper and turn arounder…well,anyway,  I was trying to turn her round, a real task as she was longer than my arm span and   wanted to be off… and all I could think about was BIG brass twin screws out of sight as i tried to shuffle my hands along the gunnels, when she decided to give me a little squirt of burning wet steam in the face….when I got my eyes open she was heading full chat across the pond! my dad was running around the edge, in chest waders, and some how got there in time….I laughed about it later but didnt dare at the time! But I will always remember the sound, whirring from the valve gear on the inline twin engine and the gearing to the twin sterntubes and contra rotating twin screws , and a kind of howl, nothing like the i/c engines I was used to. I’m going to go now and try to scan the pages from Model Engineer, and try to post some photos so wish me luck!    

[Vinnie BraniganParticipant @vinniebranigan92297]

Oy!  Gary, stop trying to post pictures so big.  It won’t work and I have to delete them.  Use the tool bar!

[gary smithParticipant @garysmith96394]

 sorry Vinnie, not very good with computers.  The pics I was trying to scan were 3 pages from "Model Engineer"  pages 308 to 340 of the April 1 1954 issue. Any advice on how to do it properly would be appreciated. I am using a Lexmark scanner/printer and my computer is running windows vista. I also have some photos but wont post them either until I know how to do it.  

[gary smithParticipant @garysmith96394]

[gary smithParticipant @garysmith96394]

thats the first page but the next is too BIG!

[Vinnie BraniganParticipant @vinniebranigan92297]

What are you using to reduce their size Gary?

Vinnie 

[Vinnie BraniganParticipant @vinniebranigan92297]

Gary, how big is each image?  I mean their file size?

Vinnie 

[gary smithParticipant @garysmith96394]

 unable to post anything at the moment. I was using the 12 year old computer "expert".  Our kid’s not quite as clever as he thought!  Still got more idea than me though! I’ll get this done properly when my daughter is here next. A true expert. To be continued…Sorry again for messing up your site.

[Rick Benson 1Participant @rickbenson1]

Hi Gary,

I just chanced on the forum and saw you original post. There are still regattas at Victoria Park and I am sure they would love to see you and the boat and offer all the help required. If you go to the MPBA website there are contact details in the straight running section (get back to me if problems) I did check with my Dad who remembers the boat and Mr Gates. 

The speed would have been more modest (8 mph maybe) but as you say when you are in the water they all seem pretty fast. 

With regard to flash steam in model boat circles this has always referred to a mono tube boiler rather than the flash evaporation system previously described.  The  record holding steam Hydro was described in 5 articles in the model engineer (starting 19th Oct 1990) by the builder Bob Kirtley. Another point of reference would "Experimental flash steam" written by my Dad, John Benson and Alan Rayman who is still running straight runners.  I can say this safely as there are no longer royalties paid to the authors so no sneaky plugging going on. Tee Publishing are the people supplying this now.

Best of luck with the restoration project.

 Rick Benson

[Author]

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