Which of the Bargepusher props did the HSD wear?

[Nudge]

That 3 blade prop that Jon is showing looks like it was made from 3 oversize soup spoons stuck to a hub!

[Oyster 49]

Good summary that Charles.

Nudge, soup spoons are highly developed

[Charles uk]

That's a good analogy Nudge, now take a blade from the 4 bladed prop & try eating your soup, loosing weight?

Which soup spoon works best?

[headdownarseup]

Here's my view on things.

Just by looking at the same "family" of props, and by that i'm talking about wartime and before here, if what Charles is saying is correct then i would have thought the prop for a bargepusher would have to look vaguely the same but bigger. Broadly speaking with a similar looking shape to the blades but bigger.Maybe even with more blades, such as all the later bargies.
Take another look at the below photos again and you'll see that the 3 bladed prop looks as though the blades have been "clocked" to the right. All the props i've seen for a straight leg Marston and any of the SD or SDP motors appear as the blades are "clocked" to the left. This 3 bladed is going the wrong way for starters. The hub of the prop doesn't even match the gearbox, not even slightly. If you were to look at any seagull from ALL ages, you'll see the prop fits very nicely against the gearcase, with a very similar dimension across the very end of the gearcase where the prop shaft comes out and the central hub of the prop. This 3 bladed prop doesn't come close to looking right. Why then, would a small company like British Seagull in a time of war have just 1 motor in the line-up that looks completely different to all the others that came before and after it. Something is definitely not right with this prop. I strongly believe this 3 bladed prop is a copy from something else that's been cleverly adapted for using the seagull drive spring. I've seen 5 of these props now, all of them fitted to 102 bargepushers as they're probably the only seagull gearbox they will fit, but not all of them were wartime either.There is a very definite pattern that seagulls follow. Big differences in prop hubs against the gearcase doesn't happen anywhere in the seagull motors. They ALL fit very nicely. Why are we so hung up on 3 bladed egg beaters being correct for early bargepushers. To my eye if it doesn't LOOK right it probably isn't right.

http://www.saving-old-seagulls.co.uk/ma ... arston.gif Look closely at how these blades are "clocked" to the left, same as any other wartime or Marston "family" prop.

AND here's another SD prop just to make sure we're all seeing the same things, "clocked" to the left.(slight differences aside with the actual shape and width of some of these, they're all "clocked" in the same direction, even the props with a sheer pin system)
And now compare this ugly 3 bladed prop again. ITS "CLOCKED" THE WRONG WAY. as well as not fitting correctly against the gearbox. WRONG WRONG WRONG!!!!!

Are we starting to understand this now?

Jon

[Charles uk]

If you look at any of the props from the "swept back" family from directly above the hub, they seem to be fairly symmetrical with an equal amount of blade either side of the centre line, apart from the Marston twin.

The blade shape, profile, aerofoil shape & polished finish, all fit the "swept back" family traits as does the material they're cast from, Birmabright.

The hub differences that Jon pointed out are logical if you add in the time frame that I think they were made in, Wartime!

During the war Aluminium was a strategic resource, as it was mined & shipped from Canada via the North Atlantic, if you weigh both of these props you can calculate how many you can manufacture from 100 kilos of aluminium, not including any casting wastage,
4 bladed @ 1.100 kilos each = 91,
3 bladed @ 0.780 kilos each = 128.
Now I'm not very good with money, but I can see the advantages (both of the props weighted, showed similar signs of tip wear).

As for "not very streamlined" in their hydrodynamic profile, these props rotate at 900 revs per minute maximum & are expected to push a large amount of water slowly so they retain a good grip on the water, they're barge pushers, not ski boat motors.

It's the lower unit with an oil filler cap & slotted water inlet that damages my argument.

I've only seen 3 of these props, the one I got from you, the one complete HSD I inspected many years ago when CharlesP & I were getting an overview of the SD series, & the "hunk of junk" one, so you've got me beat there Jon.

The 3 bladed Bargepusher prop is just too elegant & well made to be a member of the cloverleaf family!

Jon pull the lower unit from both motors in your picture as I'd really love to know if both pinion shafts are cotton reel bush types, any CIESS stamps on them?

[headdownarseup]

OK
The 2 bargepushers i have are AHC9560L and THC something or other. I think we can safely disregard the THC as having a "cotton reel" bush, nor will it have a CIESS stamp. My THC is a 1962 motor which puts things well after the end of the war, and it's this motor with the slotted inlet and screwed end cap.

AHC9560L doesn't have a CIESS stamp either as from the serial number it was made well after the war in around 48/49. It also does not have a "cotton reel" bush inside the pump housing as it has a "sub ejector", BUT it does have 2 oil nipples within the gearcase just like any other motor of the same or similar time period. 1948/9 seems to coincide with when the sub ejector pumphousing was first introduced, so on that basis i consider AHC9560L to be ok in that respect but it doesn't help clear things up with "cotton reel" bushes.

Cotton reel bushes are normally fitted to a straight out back pump housing as you know, just like any SD, SDP etc.
This is where some of the problems exist in that due to the scarcity of a genuine HSD with none of the bits being swapped from day one, the likelihood of seeing an unmolested 102 bargepusher from this era is a pretty tall order.
I think it highly unlikely that BS would want to "alter" the build specifications that much just to suit 1 specific motor type during a tense time as ww2. Keeping things simple from a production point of view i think it perfectly reasonable that there was 1 generic specification (aside from gearbox and prop) that all 3 motor types would have been made for example the short water jacket the same carb the same fuel tank etc. etc. It's only when we start looking at gearboxes and props that there is a distinct difference between the conventional 2.5 to 1 boxes and the Bargepushers. Everything else is basically the same within this group of motors.
SD's with their clutched gearbox, SDP's with a direct drive gearbox, both motors with the same generic prop and pumphousing.
Looking at this logically, all the components from the pumphousing up to the fuel cap are all pretty much the same for all 3 motor types give or take a few small detail changes. That bit is easy enough to understand.

I'm not entirely disagreeing with the concept that an HSD had a 3 bladed prop. I think you might be right, but looking at things from a wider perspective, every single prop and gearbox fitted to literally any seagull looks as though it's meant to be there. Goes back to my idea that my old 3 bladed prop looked as though it came from something else just by how it looks when it's fitted onto a plus gearbox. I can imagine a proper 3 bladed prop from an HSD would look as though it's made to measure with the same general dimensions in the prop hub and the gearbox its being fitted onto. (if it looks right it is right) I know these aren't fast by any stretch of the imagination, but just the general appearance i think really does matter when it comes to bargie props.Every other seagull has the same feature, so why would an HSD be any different. I can't see it myself. Aside from how the water flow behaves as it's passing either side of the gearbox, with a smaller prop hub a good proportion of each blade is being masked by the gearcase, which to my mind defeats the object of the prop being able to "grip" as there's basically even less of the blade's surface area that's being put to any use no matter how slow or fast that prop is turning. With a prop hub that matches the same general dimensions as a "normal" 4 bladed plus prop, it looks right, as though it was meant to be there by design. I'm not very good at fluid dynamics but even i can see the importance of this feature. The number of blades be it 3 or 4 will no doubt have an overall effect on how fast the engine manages to rev (not that anyone would really want to try waterskiing behind a smelly old seagull ), the effect of the gear reduction will obviously slow the prop down, the shape and pitch of each blade (and to some degree the rake as well) will have an effect on how much water it can push, and how streamlined the overall appearance actually is comes down to design. All of these things are important i think. All things being equal, a wartime Bargepusher would have these same features as anything else that came before or after it.


I'm not sure i would agree 100% in that a swept back prop is more or less equal either side of this centreline, as i mentioned previously the blades are "clocked" slightly to the left which have the trailing edge of each blade as being the widest part of the blade along its centreline as a datum. But i get what you're talking about here. Sort of symmetrical(ish) i suppose.

Jon

[Charles uk]

My point about these pinion shafts is how did Seagull retrofit these wartime designs & possibly castings (if birmabright), was it a shorter pinion shaft or a different water pump impeller or a bodged water pump housing, we need to know the transition path.

As my lower unit is fitted with a cotton reel bush pinion shaft & water pump impeller.

[pat777]

Just posting these "pictures" beside each other for easy comparison of "clocked" to the left versus "clocked" to the right.

Something is definitely not right with this prop. I strongly believe this 3 bladed prop is a copy from something else that's been cleverly adapted for using the seagull drive spring. I've seen 5 of these props now,

I'm with you Jon up to a point, I agree that the three bladed prop, although a very beautiful prop in my opinion, does look a little "odd/ugly/out of place" on the gearbox, however the fact that you have seen five of the props now at this stage fitted to barge pushers would give more than a little weight to the alternative argument.

propeller.JPG (62.42 KiB) Viewed 7122 times

propeller 2.JPG (61.63 KiB) Viewed 7122 times

[pat777]

Poster from the late 1950's.

http://www.britishseagullparts.com/imag ... e50s-3.jpg

[headdownarseup]

Charles, you're over thinking again!

The pinion length for a clutched 2.5:1 or direct drive 2.5:1 box is the same for both motors.Same impellers (slightly different innards to the gear mechanisms though) but largely the same between the 2 types.

I'm fairly convinced that due to seagulls manufacturing standards ,with a PLUS gearbox the pinion will be the same length as all of the later PLUS gearboxes for 102's. No hint of retro-fitting anywhere no matter which type of pump housing the motor is wearing. I can see no reason why BS would need a different length for its pinion in the PLUS gearboxes.(you'd end up with a longer or shorter drive shaft as well if this was true) Lubrication is another subject though.Cotton reel bushes with its external oil nipple (from my experience) only EVER appear with the earlier pumphousings (straight out back) and the impellers i can well imagine are the same for the SD,SDP and HSD. Post war motors change a tiny bit, but not by much until we get to around 48/49 when "sub-ejector" comes into production, and of course there's no "cotton reel" bush inside a sub-ejector. Pretty much everything else inside these gearboxes are largely untouched though.

Fast forward 70 odd years and a few "bitsa's" make an appearance though, probably built from all sorts of stuff both old and new, and maybe this is where some confusion has crept in? Seagulls "inter changeability" has a lot to answer for at times.

Aside from any ministry stamping and weird numbers, these gearboxes don't really change massively apart from the obvious external changes like the pump housing for example. Later on in production it's true, there are a couple of small detail changes like the omission of the oil nipples, the addition of a drain/fill plug in the end cap, a bit later still a change from holed inlets to slotted inlets, and a painted finish as opposed to the earlier polished finish. BUT, just about all of the components inside the gearbox can be traced back to wartime and possibly a bit earlier. That's the point i was trying to make. Seagulls manufacturing standards i think wouldn't allow for "odd" changes halfway through production unless it was found imperative that a re-design to some of the components was called for.

We can speculate to our hearts content as to which design of prop these earlier "bargepushers" actually wore. 3 or 4 blades, skinny or fat hubs,we'll have to wait and see if there are any others hiding away. I'm confident there will be, but probably not that many though.


Nice pics Pat.
Overall, quite a prolific motor the 102 in all its flavours. A motor that was in production for over 35 years possibly more (with some of the recently seen very late models) The granddaddy of them all.

Jon

[Charles uk]

If you read my post again Jon.

As my lower unit is fitted with a cotton reel bush pinion shaft & aluminium water pump impeller.

I think your under thinking Jon!

That's why I suggested you look in yours, so unless your wrong there are 2 different length pinion shafts.

We don't have to speculate, just examine the facts we're certain of

Birmabright Prop,
Prop from the swept back family,
Lower unit Birmabright,
Pinion shaft long series for the SD cotton reel bush drive shaft
Water pump impeller SD type

And then examine the balance of probabilities!

[charlesp]

I have a fairly early AHC; it's a standard shaft motor cursed with those awful aluminium "G" clamps that only lasted a short time, and it has what looks exactly like the three bladed prop that is illustrated above. It too doesn't follow the contours of the gearbox, and the recess for the prop spring is cut out of it rather than cast into it. Please don't ask me the serial - the thing is almost buried - but another interesting feature is a steel bayonet tank that has a slightly different finish under the paint. Charles I think I showed you it once.

Given that a few of these props have surfaced on HD 'boxes I'm open minded about them being standard equipment. It's true they all conformed to the flowing lines of the gearbox, but from the OJ through ON and OP and SN and SD series they were basically the same prop in terms of blade format.

Pat 777 I would put those ads a couple of years earlier than "late fifties".

As with every surviving motor I'm always aware that swapped bits are commonplace and originality is scarce.

[pat777]

Pat 777 I would put those ads a couple of years earlier than "late fifties".

Thanks Charlesp, sorry about that, once again I'm relying on an outside source for my late fifties statement.

This is taken from the website I found the poster on. http://www.britishseagullparts.com/ads.htm

Late 1950's Poster
This 20" by 26" poster shows the latest models of the time. They include 'The 102', 'The 102 Plus', 'The 40 Minus' and 'The Super 40 Plus'. On the other side are artist renderings of Seagulls at work.

So maybe earlier say 1955 or earlier again?

[Keith.P]

That's the problem with a lot of seagull advertisings, If you look at all the seagulls in that ad, they all have a flying seagull tank logo's, If you look at the bottom of the ad, it shows the sailor man, not a flying seagull, So 50's pictures used on a later ad.
Or I could be totally wrong.

[pat777]

According to my source this advert was taken from yachting monthly 1955. There seems to be a lot of emphasis on "Now" as in "now in 1955 we have four bladed propellers."

http://www.britishseagullparts.com/imag ... -May55.jpg




According to CharlesUK list,

2) "Clover leaf family,
manufactured from 46/47 from cheap casting aluminium, polished for several years until they started painting them, the "bow tie" was the first of this family, none of them had a great blade shape & were crude looking compared with the "swept backs" & must have been cheaper to produce, cheaper alloy & lower finish standard,

So my question is when exactly was the four bladed propeller introduced and why so much emphasis on the "Now" in the advert in 1955? The advert in 1955 would leave a person with little historical knowledge of British Seagull(ie.me) to believe that the four bladed propellers were only a new thing in 1955.

The HSD 102 plus outboard was manufactured in 1946.

There are 4 families of props manufactured by Marston then by British Seagull.

1) "Swept back" Marston style family,
manufactured from mid 1931, to early to mid 46 (at a guess), cast from Birmabright (7% Magnesium with good salt water properties) until the last few SD 2 blades that were cast from a lower spec alloy & look greyer, these all were very well finished with a elegant blade profile of a much thinner section with an aerofoil shape, highly polished & they look expensive compared to their younger relatives.

2) "Clover leaf family,
manufactured from 46/47 from cheap casting aluminium, polished for several years until they started painting them, the "bow tie" was the first of this family, none of them had a great blade shape & were crude looking compared with the "swept backs" & must have been cheaper to produce, cheaper alloy & lower finish standard,

3) Hydrofan family,
not an attractive prop but a efficient one & I'm sure all of us can identify one of these, when they first appeared they were recommended as a performance upgrade for earlier models, painted not polished

4) Weed free family,
everything after the Hydrofan, some with internal springs & many external, more prop shaped than the clover leafs, but none could be described as elegant, painted with low standard finish.

Oddities
Marston twin with it's cast bronze 2 & 3 bladed "swept back" family style prop,
Some inboards were fitted with a folding bronze sail drive prop,
5R fitted with a Yamaha prop.