Propeller For Horizon 35 Advice Please.

[Microbe]

Hello All,

the propeller for my Horizon 35 has been sent off the repair last week to Steel Development. I've been contacted to discover that it is beyond repair due to electrolysis corrosion. They have advised that they can obtain a replacement which will be identical to the 15 inch (not sure of pitch) that was on the boat.

I have no idea if the prop on the boat was the original. It could have been fitted as it was available (but not ideal) when replacement was needed, at some stage, over the years.

When enquiring about the best option for the replacement (size and pitch) it starts to become difficult, as the calculation from Steel comes out as 22 x 13. This seems excessively large and I would need to check hull clearance.

Can anyone advise what thay have fitted to the Horizons over the years and what may best suit this boat for pottering about on the Broads?

Horizon 35, 35 x 12 feet, 1500 BMC diesel, Newage 2:1 gearbox.

Thanks

Microbe

[Mouldy]

Try using this calculator to establish the size you require:

https://vicprop.com/displacement_size_new.php?action=calculate
 

You need to know available clearance, though.  Whilst the optimum size may be larger than your existing prop, if it won’t fit, you’ll need to compensate by using a four blade or a greater pitch.

Be aware though, that the lead time on a new prop is lengthy.  I waited about ten weeks for one for our own boat and Peachments have quoted 19 weeks for a replacement for our syndicate boat.

[Microbe]

1 hour ago, Mouldy said:

Try using this calculator to establish the size you require:

https://vicprop.com/displacement_size_new.php?action=calculate
 

You need to know available clearance, though.  Whilst the optimum size may be larger than your existing prop, if it won’t fit, you’ll need to compensate by using a four blade or a greater pitch.

Be aware though, that the lead time on a new prop is lengthy.  I waited about ten weeks for one for our own boat and Peachments have quoted 19 weeks for a replacement for our syndicate boat.

Thank you Mouldy, a really useful website. I will contact Steel Development again, as I suspect the calcs are distorted by my advice of the BMC power output as 35hp. Further research from the Web suggests something like 22hp at 2200rpm. This gives a smaller prop size, but similar pitch dimensions.

[Smoggy]

Have a chat with Paul at Clements he knows his stuff pretty well, he told me what my early 80's boat was fitted with from new and re-fettled my props and they were spot on, as said new props have a long lead time as they are usually cast and machined to order.

I didn't think steel developments did much with shaft drive props, always thought they were more outdrive/outboard and repairs.

[NeilB]

Pretty sure the 1.5 was 35hp at 3,000rpm when new.  If it's done several thousand hours since being rebuilt then some horses will have escaped, hard to say how many - up to 5hp maybe.

Just give the prop maker the boat and engines full details and they should be able to work it out for you.  Although 22" diameter does sound a lot, 15 sounds much closer to what I would expect.  

[Mouldy]

40 minutes ago, NeilB said:

Pretty sure the 1.5 was 35hp at 3,000rpm when new.  If it's done several thousand hours since being rebuilt then some horses will have escaped, hard to say how many - up to 5hp maybe.

Just give the prop maker the boat and engines full details and they should be able to work it out for you.  Although 22" diameter does sound a lot, 15 sounds much closer to what I would expect.  

Using the calculator and guessing the hull draft at about 2.5 ft, the size comes out at about 15x10  for a three blade.  Like Neil said, a 22” diameter does sound far too big, even if you have sufficient clearance.

[JanetAnne]

Don't forget to factor in the 2:1 gearbox here....

[Mouldy]

1 hour ago, JanetAnne said:

Don't forget to factor in the 2:1 gearbox here....

All dealt with in the calculations on the Vicprop website

https://vicprop.com/displacement_size_new.php/?m=1

[Microbe]

Hi All,

just to keep you updated. I have revised the calculation for power from the BMC 1500 engine to a modest 20HP at 2000rpm.

In another discussion with Steel Development the recommendation is a propeller of 20" x 12". Using the Vicprop website recommended by Mouldy (thanks again), the recommendation is 18" x 13".

I have also spoken to George at Ludham Bridge Boatyard, who was most helpful in suggesting contacting Richardsons boatyard to ask if they will share the original design data.

I have emailed Paul Richardson today and await a reply. Fingers crossed!!

Microbe

[MargeandParge]

22 minutes ago, Microbe said:

Hi All,

just to keep you updated. I have revised the calculation for power from the BMC 1500 engine to a modest 20HP at 2000rpm.

In another discussion with Steel Development the recommendation is a propeller of 20" x 12". Using the Vicprop website recommended by Mouldy (thanks again), the recommendation is 18" x 13".

I have also spoken to George at Ludham Bridge Boatyard, who was most helpful in suggesting contacting Richardsons boatyard to ask if they will share the original design data.

I have emailed Paul Richardson today and await a reply. Fingers crossed!!

Microbe

If you are lucky they mighty have one kicking about either new or a second hand one. 

Kindest Regards Marge and Parge 

[Microbe]

6 minutes ago, MargeandParge said:

If you are lucky they mighty have one kicking about either new or a second hand one. 

Kindest Regards Marge and Parge 

Yep I was quietly hoping that too, but let's see!

[Mouldy]

1 hour ago, Microbe said:

Hi All,

just to keep you updated. I have revised the calculation for power from the BMC 1500 engine to a modest 20HP at 2000rpm.

In another discussion with Steel Development the recommendation is a propeller of 20" x 12". Using the Vicprop website recommended by Mouldy (thanks again), the recommendation is 18" x 13".

I have also spoken to George at Ludham Bridge Boatyard, who was most helpful in suggesting contacting Richardsons boatyard to ask if they will share the original design data.

I have emailed Paul Richardson today and await a reply. Fingers crossed!!

Microbe

If 18x13 is the correct size, depending on whether it’s l/hand or r/hand and shaft diameter of 11/4” (1.25 inch), I may know where you can get one.

[Microbe]

1 minute ago, Mouldy said:

If 18x13 is the correct size, depending on whether it’s l/hand or r/hand, I may know where you can get one.

Thanks Mouldy, I've just had a phone call from Paul Richardson. He is lifting one of the Horizons tomorrow and will advise what size is fitted. I believe that the current prop is left hand......, but will await Pauls update.

I really appreciate all the help and responses from you all on this one!!

Microbe

[Mouldy]

30 minutes ago, Microbe said:

Thanks Mouldy, I've just had a phone call from Paul Richardson. He is lifting one of the Horizons tomorrow and will advise what size is fitted. I believe that the current prop is left hand......, but will await Pauls update.

I really appreciate all the help and responses from you all on this one!!

Microbe

I wouldn’t necessarily go by what’s fitted.  With some hire boats, they’re underpropped anyway.  The engine spins faster to turn the alternator and feed more power to the batteries.  Also, if the original was damaged, they could have fitted whatever was laying in the shed to get the boat back into service.  Just a couple of points to think about.

[JawsOrca]

Another potential contact:

https://shop.tnorrismarine.co.uk/

They helped us prop on a sailboat we rebuilt with all unique set up and got it bang on. They can also adjust and repair. +1 as mouldy mentions. 

Also be aware that you may not get it right first time, I'm still struggling with a prop for our boat and I'm on the second prop, we really need an in between, though I'm just being fussy. So someone like T Norris who can adjust may be needed. 

[Smoggy]

A new prop from clements usually gets a free re-pitch if needed to back up above advice about first time luck, even the pros recognise that.

They don't pay for the lift and launch though. 

[oldgregg]

17 hours ago, Mouldy said:

I wouldn’t necessarily go by what’s fitted.  With some hire boats, they’re underpropped anyway.  The engine spins faster to turn the alternator and feed more power to the batteries.  Also, if the original was damaged, they could have fitted whatever was laying in the shed to get the boat back into service.  Just a couple of points to think about.

Definitely! All of these points are very valid.

[Vaughan]

18 hours ago, Mouldy said:

 With some hire boats, they’re underpropped anyway.  The engine spins faster to turn the alternator and feed more power to the batteries.

Rather, fit a smaller pulley on the alternator.

18 hours ago, Mouldy said:

Also, if the original was damaged, they could have fitted whatever was laying in the shed to get the boat back into service.

That is very true and very often happens.

[C.Ricko]

The horizon craft 35s were usually fitted with 16x14 lh propellers normally  bored to 1” 3/8 with a 5/16 keyway, 

hope this helps.. 

 

[Meantime]

8 minutes ago, C.Ricko said:

The horizon craft 35s were usually fitted with 16x14 lh propellers normally  bored to 1” 3/8 with a 5/16 keyway, 

hope this helps.. 

 

That's interesting. I had my prop redressed last year whilst it was out of the water. It was stamped 16x14 RH. It's an Alpha 35ft, which I think is basically the Bounty hull.

[Mouldy]

20 minutes ago, Meantime said:

That's interesting. I had my prop redressed last year whilst it was out of the water. It was stamped 16x14 RH. It's an Alpha 35ft, which I think is basically the Bounty hull.

Was the Alpha 35 essentially not the F B Wilds Bermuda hull?

[Meantime]

15 minutes ago, Mouldy said:

Was the Alpha 35 essentially not the F B Wilds Bermuda hull?

I could be wrong, but I thought the Bounty hull had the low wash lip at the front and the Bermuda didn't?

Very similar though.

[NeilB]

50 minutes ago, Meantime said:

I could be wrong, but I thought the Bounty hull had the low wash lip at the front and the Bermuda didn't?

Very similar though.

Mine's a 42 and does have the lip, there are 2 x 35's in the same section at Sutton Staithe - last week I noticed one has the lip and the other doesn't!!  The Alphas are based on the old Wild's hull, pretty sure no one else used the Bounty hulls for anything.

[Microbe]

On 21/03/2023 at 13:24, C.Ricko said:

The horizon craft 35s were usually fitted with 16x14 lh propellers normally  bored to 1” 3/8 with a 5/16 keyway, 

hope this helps.. 

 

Thank you the dimensions for the shaft match my measurements exactly. I have completed the spreadsheet for T Norris to see what is recommended, together with cost and lead in time.......

[Microbe]

Update:

Thank you all for your help and advice on my enquiry. It has been a learning journey and, whilst still very much a novice, I am more informed now.

Both Clements and T Norris were very helpful in providing advice. Paul Richrdson confirmed the dimensions on his hire craft as 16x14 left handed, as Meantime advised.

On this basis I ordered 16x14 from T Norris and fitted it this week. The boat will return to the water shortly and I will find out what changes (if any) are noticeable from the 15x13 that was fitted previously.

I'll report back in the coming weeks.......

Microbe.