Barbary Ketch 32 stern tube diameter

Sorry to be a bit late to the party! So Dabchick has been re engined with a vetus 42 hp in 2005. We have a dripless low maintenance shaft seal, so low maintenance that i have forgotten the make!

We replaced the shaft with a 30mm one so when i replaced the cutlass bearing a few years zgo we had one that is imperial outside to fit the stern tube and 30mm metric inside but the engineer who did that found a replacement easily but in the UK.

With such old boats, i agree that one size may not fit all and uoy might have to measure up and order.



Dabchick is back in the water so i can't easily measure the stern tube, good luck!
 
chubby said:
Sorry to be a bit late to the party! So Dabchick has been re engined with a vetus 42 hp in 2005. We have a dripless low maintenance shaft seal, so low maintenance that i have forgotten the make!

We replaced the shaft with a 30mm one so when i replaced the cutlass bearing a few years zgo we had one that is imperial outside to fit the stern tube and 30mm metric inside but the engineer who did that found a replacement easily but in the UK.

With such old boats, i agree that one size may not fit all and uoy might have to measure up and order.



Dabchick is back in the water so i can't easily measure the stern tube, good luck!
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Thank you @chubby for your reply!

Having one measurement will give me an idea but I have understood the risk involved of relying only on it.

You provided me with a very interesting information of the fact that it is possible to replace the propeller shaft for a 30mm one without any modification on the stern tube. Of course this involves a lot of other parts to be replaced (coupling on gearbox, stuffing box, cutlass bearing). I believe you had to change the propeller itself too. Is that right?

Also, what was involved when you had a vetus 42 hp fitted? Did the engine supports have to be modified?
 
Oli-Barbary-Ketch said:
Thank you @chubby for your reply!

Having one measurement will give me an idea but I have understood the risk involved of relying only on it.

You provided me with a very interesting information of the fact that it is possible to replace the propeller shaft for a 30mm one without any modification on the stern tube. Of course this involves a lot of other parts to be replaced (coupling on gearbox, stuffing box, cutlass bearing). I believe you had to change the propeller itself too. Is that right?

Also, what was involved when you had a vetus 42 hp fitted? Did the engine supports have to be modified?
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Do you have the normal Mercedes 636? If so a 30mm would be the proper size shaft if the installation was carried out now. The shaft is quite long and (probably) unsupported as I am assuming there is no bearing on the inboard end of the stern tube. On my boat which originally had a 1 1/8" shaft we changed to 30mm even though the engine is only 30hp. However the shaft is 54" long and we added a heavy feathering propeller. For extra support there is also a cutless added to the inboard bearing housing. That is removable so was machined to take the bearing and a Radice seal (48mm) . Photo shows the housing. Doubt you will be able to fit a bearing in your tube but if you do change the shaft you will need to check there is adequate clearance in the tube and ensure the shaft is centralised in the tube when aligning the engine. If you do change the shaft you will need to bore the shaft coupling to 30mm and change the propeller. So probably only worth doing if changing the engine to either a Beta or a Vetus which will need a new propeller anyway.

As to shaft seals. I prefer lip seals to face seals. Deep Sea, PSS and some Las Drop are face seals. The first of those has a very chequered history, but the other 2 seem well engineered but to my mind are overcomplicated for such a simple job. Face seals are very common in industrial applications where shafts are fixed, but you can see what is required to make them work in a boat where one face is fixed to the boat and the other to the shaft that moves back and forward plus side to side. Maintaining the seal relies on compression of the bellows staying at the preset level. Faces also tend to stick together if left unused so need care to unstick before using the boat after a period of non use. If a Radice won't fit your tube then a Tides series one is a good choice as it uses lip seals and has a good size choice of bellows to fit the stern tube.
 

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Oli-Barbary-Ketch said:
Thank you @chubby for your reply!

Having one measurement will give me an idea but I have understood the risk involved of relying only on it.

You provided me with a very interesting information of the fact that it is possible to replace the propeller shaft for a 30mm one without any modification on the stern tube. Of course this involves a lot of other parts to be replaced (coupling on gearbox, stuffing box, cutlass bearing). I believe you had to change the propeller itself too. Is that right?

Also, what was involved when you had a vetus 42 hp fitted? Did the engine supports have to be modified?
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I choose the vetus M4.17 because it fitted the engine supports with minimal modifications, that was some years ago and the model number has changed but i expect the foot print is similar. I changed to a Darglow fearherstream to improve performance sailing and astern and i have been happy with both of those.

The engineer who last did the cutlass bearing had no difficulty sourcing a bearing that was imperial outside and 30mm metric inside, a common requirement for old boats!
 
Tranona said:
Do you have the normal Mercedes 636? If so a 30mm would be the proper size shaft if the installation was carried out now. The shaft is quite long and (probably) unsupported as I am assuming there is no bearing on the inboard end of the stern tube. On my boat which originally had a 1 1/8" shaft we changed to 30mm even though the engine is only 30hp. However the shaft is 54" long and we added a heavy feathering propeller. For extra support there is also a cutless added to the inboard bearing housing. That is removable so was machined to take the bearing and a Radice seal (48mm) . Photo shows the housing. Doubt you will be able to fit a bearing in your tube but if you do change the shaft you will need to check there is adequate clearance in the tube and ensure the shaft is centralised in the tube when aligning the engine. If you do change the shaft you will need to bore the shaft coupling to 30mm and change the propeller. So probably only worth doing if changing the engine to either a Beta or a Vetus which will need a new propeller anyway.

As to shaft seals. I prefer lip seals to face seals. Deep Sea, PSS and some Las Drop are face seals. The first of those has a very chequered history, but the other 2 seem well engineered but to my mind are overcomplicated for such a simple job. Face seals are very common in industrial applications where shafts are fixed, but you can see what is required to make them work in a boat where one face is fixed to the boat and the other to the shaft that moves back and forward plus side to side. Maintaining the seal relies on compression of the bellows staying at the preset level. Faces also tend to stick together if left unused so need care to unstick before using the boat after a period of non use. If a Radice won't fit your tube then a Tides series one is a good choice as it uses lip seals and has a good size choice of bellows to fit the stern tube.
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I am not sure about the "normal" but yes engine is Mercedes 636. Your explanations are clear thank you. Not planing to replace the propeller shaft and hoping not having to do so but good to have your feedback.

Regarding the shaft seal we will probably go for a Tides Marine series one.

Do you own a Barbary Ketch as well?
 
chubby said:
I choose the vetus M4.17 because it fitted the engine supports with minimal modifications, that was some years ago and the model number has changed but i expect the foot print is similar. I changed to a Darglow fearherstream to improve performance sailing and astern and i have been happy with both of those.

The engineer who last did the cutlass bearing had no difficulty sourcing a bearing that was imperial outside and 30mm metric inside, a common requirement for old boats!
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Thank you for these details.
 
I have another question which still relates to the subject as it is about a tube connected on the stern tube.

Maybe owners of Barbary Ketch like @chubby @Ardenfour will be interested.

I was reading the following page 5 in this document on the website The Barbary Class Ketch | The website for Barbary Class Ketch owners and fans everywhere.

NOTE : if the engine is laid up afloat, the tube from the stern tube should be disconnected at the engine end and blocked off, otherwise there could be a change of syphoning back to the pump.

I attach a photo on which I have added arrows 1 and 2. Number 1 is the grease so I believe what is referred to in page 5 is pipe number 2.

Can you tell me more about this NOTE please? Can this sink the boat? What is the risk involved?

Our boat Barbary Girl is all the time in the water (so she is afloat), my father in law never told me about this procedure. Unfortunately I don’t have any photo to know where the other end of this tube is plugged.

I therefore also plan to replace this tube, as it is probably old, like the boat itself.
 

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Oli-Barbary-Ketch said:
I am not sure about the "normal" but yes engine is Mercedes 636. Your explanations are clear thank you. Not planing to replace the propeller shaft and hoping not having to do so but good to have your feedback.

Regarding the shaft seal we will probably go for a Tides Marine series one.

Do you own a Barbary Ketch as well?
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No, a Golden Hind 31. Similar era and engineering. My knowledge such as it is of Barbarys comes from keeping a boat in Mitchells yard for about 10 year when they were still making them.
 
Oli-Barbary-Ketch said:
I have another question which still relates to the subject as it is about a tube connected on the stern tube.

Maybe owners of Barbary Ketch like @chubby @Ardenfour will be interested.

I was reading the following page 5 in this document on the website The Barbary Class Ketch | The website for Barbary Class Ketch owners and fans everywhere.

NOTE : if the engine is laid up afloat, the tube from the stern tube should be disconnected at the engine end and blocked off, otherwise there could be a change of syphoning back to the pump.

I attach a photo on which I have added arrows 1 and 2. Number 1 is the grease so I believe what is referred to in page 5 is pipe number 2.

Can you tell me more about this NOTE please? Can this sink the boat? What is the risk involved?

Our boat Barbary Girl is all the time in the water (so she is afloat), my father in law never told me about this procedure. Unfortunately I don’t have any photo to know where the other end of this tube is plugged.

I therefore also plan to replace this tube, as it is probably old, like the boat itself.
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Depends on where the water take off is on the engine or pipework. Is there an antisyphon downstream of the water pump, usually in the pipe that exits the heat exchanger and injects the water into the exhaust.
 
Oli-Barbary-Ketch said:
I have another question which still relates to the subject as it is about a tube connected on the stern tube.

Maybe owners of Barbary Ketch like @chubby @Ardenfour will be interested.

I was reading the following page 5 in this document on the website The Barbary Class Ketch | The website for Barbary Class Ketch owners and fans everywhere.

NOTE : if the engine is laid up afloat, the tube from the stern tube should be disconnected at the engine end and blocked off, otherwise there could be a change of syphoning back to the pump.

I attach a photo on which I have added arrows 1 and 2. Number 1 is the grease so I believe what is referred to in page 5 is pipe number 2.

Can you tell me more about this NOTE please? Can this sink the boat? What is the risk involved?

Our boat Barbary Girl is all the time in the water (so she is afloat), my father in law never told me about this procedure. Unfortunately I don’t have any photo to know where the other end of this tube is plugged.

I therefore also plan to replace this tube, as it is probably old, like the boat itself.
Click to expand...
17433330179523927717582629831596.jpg
 
Ardenfour said:
I can't access the stern tube from inside, mine is slightly different to yours in that the stuffing gland is forward of the sterntube. In any case it's glassed in, so I couldn't measure the tube size directly.
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Looks the same as in post#29 with the stuffing box on a hose. If so then the diameter of the tube is likely to be 48mm so a Radice seal will fit straight on.
 
Ardenfour said:
I can't access the stern tube from inside, mine is slightly different to yours in that the stuffing gland is forward of the sterntube. In any case it's glassed in, so I couldn't measure the tube size directly.
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Thank you very much for taking the time to make all these photos.

To be honest I was somehow hoping for a external diameter of 44.45mm (1 3/4") which seemed to often match a 28.6mm shaft (1 1/8") but you measured more (close to 1 7/8").

@Tranona you said that a Radice seal will fit straight but this would be true only if the propeller shaft was 30mm and not 28.6mm like ours. Am I correct?

Regarding the water supply to the stern gland, I will have to have a look onboard as we don't have a system exactly like yours @Ardenfour

Thank you for all your time and answers this is so kind of you I really appreciate it.
 
Oli-Barbary-Ketch said:
Thank you very much for taking the time to make all these photos.

To be honest I was somehow hoping for a external diameter of 44.45mm (1 3/4") which seemed to often match a 28.6mm shaft (1 1/8") but you measured more (close to 1 7/8").

@Tranona you said that a Radice seal will fit straight but this would be true only if the propeller shaft was 30mm and not 28.6mm like ours. Am I correct?

Regarding the water supply to the stern gland, I will have to have a look onboard as we don't have a system exactly like yours @Ardenfour

Thank you for all your time and answers this is so kind of you I really appreciate it.
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If you look on p35 of the catalogue you will find the Radice in imperial 1 1/8" bore and 48mm stern tube. Important to get exactly the right size. A water feed is not essential as the feed tube from the seal can be used as a vent to ensure there is always water in the tube and it fills when you launch. However as you seem to have one already makes sense to connect it.
 
Tranona said:
If you look on p35 of the catalogue you will find the Radice in imperial 1 1/8" bore and 48mm stern tube. Important to get exactly the right size. A water feed is not essential as the feed tube from the seal can be used as a vent to ensure there is always water in the tube and it fills when you launch. However as you seem to have one already makes sense to connect it.
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I see 1 1/4" for the propeller shaft but not 1 1/8" in page 35 for the Radice :unsure:
 
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