Not Used To "Industrial Strength" Narrow Boat Engineering.

[alan_fincher]

Long overdue is investigating "Sickle's" stern tube, and particularly the fact that there didn't appear to be any adjustment left on the nuts to tighten it down any more.

 

I knew it was a "meaty" bit of kit, but didn't realise that none of the spanners in my tool box were anywhere like asa big as the nuts. I managed eventually to find one large enough, and an adjustable for the lock nuts.

 

Now I had already been into the local chandlers to see if they still had large packing I remembered seeing there when I failed to buy small packing (!). We have all sizes said the man, and proceded to produce 1/4" 5/16" and 3/8" sizes.

 

I had had my doubts at the time that even 3/8" would be correct and it seems quite rightly so - I could easily insert a 13mm drill bit down where it need to go, so it needs to be in a 1/2" size. This certainly isn't stocked by the likes of Midland Chandlers, so will probably need mail ordering from somewhere like ASAP or Norris.

 

The packing I could see looks "interesting", with an apparently incomplete ring the last one in - I had hoped to just add an extra ring or too, but am now wondering if I'm brave enough to pull it out and start again. (No weed hatch so little opportunity to try and stop water getting in at the outer end......)

 

It seems if you have an older boat even what should be the trivial jobs start to take longer.

[Chris-B]

Ring t Norris at isleworth and speak tonjonathan for packing Alan

020 8560 3453

Chris

[Tim Lewis]

Long overdue is investigating "Sickle's" stern tube, and particularly the fact that there didn't appear to be any adjustment left on the nuts to tighten it down any more.

 

I knew it was a "meaty" bit of kit, but didn't realise that none of the spanners in my tool box were anywhere like asa big as the nuts. I managed eventually to find one large enough, and an adjustable for the lock nuts.

 

Now I had already been into the local chandlers to see if they still had large packing I remembered seeing there when I failed to buy small packing (!). We have all sizes said the man, and proceded to produce 1/4" 5/16" and 3/8" sizes.

 

I had had my doubts at the time that even 3/8" would be correct and it seems quite rightly so - I could easily insert a 13mm drill bit down where it need to go, so it needs to be in a 1/2" size. This certainly isn't stocked by the likes of Midland Chandlers, so will probably need mail ordering from somewhere like ASAP or Norris.

 

The packing I could see looks "interesting", with an apparently incomplete ring the last one in - I had hoped to just add an extra ring or too, but am now wondering if I'm brave enough to pull it out and start again. (No weed hatch so little opportunity to try and stop water getting in at the outer end......)

 

It seems if you have an older boat even what should be the trivial jobs start to take longer.

 

I seem to remember that we once bought some thick packing from Uxbridge boat centre.

 

Tim

[alan_fincher]

Thanks both.

 

I'll try T Norris tomorrow, but I note ASAP supplies also do one by the metre, so it shouldn't be too hard to source, I think.

 

(I know Norris are a long established, well respected firm - first used them decades ago - however they need to be, given what their attempt at a web-site looks like!....)

[BEngo]

Long overdue is investigating "Sickle's" stern tube, and particularly the fact that there didn't appear to be any adjustment left on the nuts to tighten it down any more.

 

I knew it was a "meaty" bit of kit, but didn't realise that none of the spanners in my tool box were anywhere like asa big as the nuts. I managed eventually to find one large enough, and an adjustable for the lock nuts.

 

Now I had already been into the local chandlers to see if they still had large packing I remembered seeing there when I failed to buy small packing (!). We have all sizes said the man, and proceded to produce 1/4" 5/16" and 3/8" sizes.

 

I had had my doubts at the time that even 3/8" would be correct and it seems quite rightly so - I could easily insert a 13mm drill bit down where it need to go, so it needs to be in a 1/2" size. This certainly isn't stocked by the likes of Midland Chandlers, so will probably need mail ordering from somewhere like ASAP or Norris.

 

The packing I could see looks "interesting", with an apparently incomplete ring the last one in - I had hoped to just add an extra ring or too, but am now wondering if I'm brave enough to pull it out and start again. (No weed hatch so little opportunity to try and stop water getting in at the outer end......)

 

It seems if you have an older boat even what should be the trivial jobs start to take longer.

 

Well, if you come up to Maffers you could probably do it in the top lock of the Aylesbury Arm-it won't be in anyone's way and you can easily put Sickle on the bottom if needed!

 

N

[alan_fincher]

Well, if you come up to Maffers you could probably do it in the top lock of the Aylesbury Arm-it won't be in anyone's way and you can easily put Sickle on the bottom if needed!

 

N

Stoppage: Aylesbury Arm Lock 12

28 Mar 2013 until further notice

Associated Regional Office: South East Waterways

 

Lock 1 (junction with mainline) is also locked to prevent boats entering the Arm.

[gazza]

Alan, try http://www.pipecenter.co.uk/ there is a branch locator page. Or alternatively look for a local plumbing and pipeline stockist. No reason to pay over the odds for gland packing at a chandlers.

[Speedwheel]

It's probably 9/16 or 5/8.

 

I bought some from James Walker.

[Timleech]

It's probably 9/16 or 5/8.

 

I bought some from James Walker.

 

9/16"? sound a bit like splitting hairs, a moment with a hammer will soon create 9/16" from 1/2" or 5/8"

 

Also it generally comes in metric sizes now, 12mm or 16mm are the common sizes. Maybe there's a 14mm, never asked.

 

Big sizes do get expensive when you buy a whole roll or box.

 

 

Tim

Edited April 12, 2013 by Timleech

[alan_fincher]

Definitely not as big as 5/8"

 

I'm sure 1/2" (13mm) will do it, but if it proves to less than a full fit I may remould it a bit in line with Tim's suggestion.

 

I'm also wondering if I should lose the "traditional" element of a greaser that is just a screw down cap in favour of the more usual "tube with a screw" type approach, because frankly it is a pain to keep refilling it, (it doesn't hold a lot).

 

However I'll wait and see if putting some new packing in reduces the large amounts of grease I have been getting through.

[XAlan W]

Definitely not as big as 5/8"

 

I'm sure 1/2" (13mm) will do it, but if it proves to less than a full fit I may remould it a bit in line with Tim's suggestion.

 

I'm also wondering if I should lose the "traditional" element of a greaser that is just a screw down cap in favour of the more usual "tube with a screw" type approach, because frankly it is a pain to keep refilling it, (it doesn't hold a lot).

 

However I'll wait and see if putting some new packing in reduces the large amounts of grease I have been getting through.

When I had Lily,I drilled,tapped,& fitted a grease nipple to the grease cup cap 2/3 pumps with a grease gun saved removing & refilling the cup each time, ,you could give it twist to check if it was full, after a time I got to be able to judge by the pressure on the gun as to when the tube was full

[Timleech]

When I had Lily,I drilled,tapped,& fitted a grease nipple to the grease cup cap 2/3 pumps with a grease gun saved removing & refilling the cup each time, ,you could give it twist to check if it was full, after a time I got to be able to judge by the pressure on the gun as to when the tube was full

 

Stern gear on older NBs was expected to be pretty much water lubricated, the grease was really more to lubricate the gland and help to keep it watertight.

 

I suspect that early motor boats had cast iron stern bearings, on a steel shaft, which would probably have been better with water lube than the presently normal bronze on stainless, but also the bearings were much longer and often with a very long gland whch would also serve as a bearing. I've never seen an original cast iron bush, they had all worn out and been sleeved with bronze even before my time. Can anyone confirm whether or not they did use CI for the bearing? It used to be quite common on ships, apparently.

 

Tim

[alan_fincher]

A word of praise for ASAP Supplies, (and the Royal Mail!)

 

New packing ordered yesterday lunchtime, and decided to pay only for standard first class post, as other options a lot more expensive.

 

Waiting for me on the doormat this morning.

 

Anybody got any waders they can lend me!

 

(ASAP were a lot cheaper than T Norris, by the way).

[alan_fincher]

Well I'm home, and my feet are completely dry!

 

Not quite what was expected when I tried unpacking the gland though.

 

I had already discovered that the last ring in looked decidedly on the weedy size for the 13mm gap present, and also that it was not a complete ring. A second piece taken out proved to be not a lot better.

 

Only when I finally dug out the third ring in did I find packing of the kind of size I would have expected, or a ring that just about reached the whole way around the shaft.

 

That ring was a long way in, hard to remove, and seemed in good nick, but clearly not the last one, and by now I was reaching in over 2", and wasn't confident of getting the next bit out, or that a flood wasn't imminent.

 

As I had easily enough depth for three rings of the new 13mm packing, and as the last ring out had been fine, I decided to stop, and refill from there.

 

All back together, although I have not yet run it up to see how much it leaks.

 

I think that the undersize packing I had taken out had only been added to give fill a gap, not for water-tightness, (without it present, the "proper packing" would not have been under compression). All a bit odd though, unless a mixture of packing sizes regularly gets put in Grand Union stern gear!

I'll see if I can post some pictures later.

[alan_fincher]

Some photos if anybody is interested......

 

Packing

 

Proper sized old ring to left, with one of the undersized rings to right. New packing for comparison below.

 

 

Dismantled, with old packing removed.

 

 

New piece of packing.

 

 

New ring part inserted.

 

 

Back together.

 

 

All the surrounding bits.

 

 

The engineering is an awful lot more heavy duty than in out leisure boat!

 

[RLWP]

 

Heavy, and a bit peculiar. The thrust from the prop is taken on a massive plummer block (good), bolted to a fabricated part (OK), about 12" tall (um), welded directly to the bottom of the hull (oh), with no side arms (aargh).

 

Hopefully there isn't much thrust to flex the hull, or have I missed something?

 

Richard

[Bee]

Plummer blocks aren`t really thrust bearings but I used one for years like that with no probs so if it works ok I think I`d leave it. Alans grease nipple / grease gun approach is what I have done on Bee, you can be certain some grease has gone in wheras I`m never very sure with the screw down thingys.

[Timleech]

Heavy, and a bit peculiar. The thrust from the prop is taken on a massive plummer block (good), bolted to a fabricated part (OK), about 12" tall (um), welded directly to the bottom of the hull (oh), with no side arms (aargh).

 

Hopefully there isn't much thrust to flex the hull, or have I missed something?

 

Richard

 

Those Dodge type bearings can be configured as thrust bearings or simple support bearings. The original arrangement on the GU motor boats was a plain bronze plummer block on a fairly flimsy A frame, rather further forward than Alan's, with a solid shaft through to the gearbox. OK, if there's a big misalignment between prop shaft and engine then Alan's could be taking a significant side load from the universal joints, the answer I suppose is to observe it in action, see whether it wobbles at all.

 

Tim

[RLWP]

It was the forward thrust on the end of the cantilevered fabrication flexing the baseplate that concerned me. However, if it works, it works I suppose

 

Richard

[Timleech]

It was the forward thrust on the end of the cantilevered fabrication flexing the baseplate that concerned me. However, if it works, it works I suppose

 

Richard

 

It might not be carrying thrust, depends on the configuration of the bearing.

 

Tim

[RLWP]

It might not be carrying thrust, depends on the configuration of the bearing.

 

Tim

 

Which would mean I had missed something, always a possibility

 

Richard

[ChimneyChain]

As I've got exactly the same set up as this, when screwing down the greaser cap what stops the grease from going right and out to the prop, where as it should be going left to the gland.

 

Darren

[alan_fincher]

It might not be carrying thrust, depends on the configuration of the bearing.

 

Tim

My assumption (up until now!) is that it is acting as support, but not taking the thrust.

 

I assumed the thrust was on the gearbox and engine, (although thinking about it that would mean the spider joints in the drive train are also being compressed and stretched, which may not be so clever, I guess).

 

I hadn't considered it too deeply, but, as you suggest, I'll try and see what happens in actual use.

[Timleech]

My assumption (up until now!) is that it is acting as support, but not taking the thrust.

 

I assumed the thrust was on the gearbox and engine, (although thinking about it that would mean the spider joints in the drive train are also being compressed and stretched, which may not be so clever, I guess).

 

I hadn't considered it too deeply, but, as you suggest, I'll try and see what happens in actual use.

 

It's often said the 'Universal joints shouldn't carry thrust'. In reality, in this sort of setup where they work through a small angle it's not a problem.

 

Tim

 

As I've got exactly the same set up as this, when screwing down the greaser cap what stops the grease from going right and out to the prop, where as it should be going left to the gland.

 

Darren

 

It'll go both ways. Yes some will be lost to the canal, giving a bit of help with lubrication on its way. Greasers usually feed in just behind the gland, ensuring that the gland does get some grease.

 

Tim

[Speedwheel]

As I've got exactly the same set up as this, when screwing down the greaser cap what stops the grease from going right and out to the prop, where as it should be going left to the gland.

 

Darren

 

I'd say it should be going right out to the prop.

 

I always use plenty of grease. Pump it full of the stuff. Grease is cheap - replacing stern gear isn't.

 

Definitely not as big as 5/8"

 

I'm sure 1/2" (13mm) will do it, but if it proves to less than a full fit I may remould it a bit in line with Tim's suggestion.

 

I'm also wondering if I should lose the "traditional" element of a greaser that is just a screw down cap in favour of the more usual "tube with a screw" type approach, because frankly it is a pain to keep refilling it, (it doesn't hold a lot).

 

However I'll wait and see if putting some new packing in reduces the large amounts of grease I have been getting through.

 

As much as I am a traditionalist - yes I would lose it. The one on Cactus drove me mad.

 

I would like the big that T.Norris sell but I don't really want to pay £222 for it.

 

http://www.tnorrismarine.co.uk/offers.php