Category Archives: Leak Hints & Tips

Notes on Drawings and Design
While in my opinion the Leak Compound is the best marine compound design on the market, it seems to be quite well known that there are a number of errors (and omissions) from the drawings for the Leak Compound. As a service to the community, I am publishing the errors I have found in the drawings and would welcome input from others as to any “quirks” they have found.

In the process I have also developed a reduction drive for the pumps (to allow the engine to rev faster) and a step-up drive for an alternator to provide power for burners, navigation lights and radio – creating the drawings for this have taught me not to be too critical of others mistakes – it’s hard … :-)

HP valve to Cylinder Joint & Lubrication

From Experience two other issues to consider

While these are not drawing errors, they have emerged over the first 3 seasons with the engine, and should be considered by builders.

HP Valve Chest to Cylinder Joint

In the BOOK the designer suggests using Araldite? as a jointing/sealing material… its not a solution, particularly for this joint.

The joint between the HP Valve Chest and the HP cylinder is problematic, as the sealing faces are very thin, and the two components are only secured by 4 bolts, which are hard to tighten and not well positioned to ensure a steam tight joint.

My first attempt was using “SteamSeal” jointing compound  – this failed quite quickly.

The second attempt was using “Heldite” jointing compound – this failed within a few hours.

My last attempt was using “Oakenstrong” gasket paper, I had resisted this, not wanting to affect the overall block dimensions. However, rebuilding with gasket paper and jointing compound (Heldite) does seem to have cured this problem.

Lubrication of “small ends”

I spent a long time chasing a knock that appeared to come from the LP small end. Rebushing the piston rod and a new pin did not cure this, and it was clear that the pin was suffering.

This was finally cured by increasing the size of the Lubtech pump units feeding these bearings and slide ways. A “black” one (0.1cc/stroke) silenced the knock instantly.

I am sure that a better builder than me might make the sideway fits better, but the lubrication points at the bottom of the piston rods have to lubricate the “small end” and the slide-ways, and so need a heavy oil flow to ensure that both bearings are supplied on each cylinder, as I think the oil preferentially flows to the slide-ways, starving the bush at the lower end of the piston rod.

Is this the end? Probably not!

Timeframe missed a bit

Well, looking back the first post here was on 8th June 2011, and we aimed to finish and launch by 26th June 2015 – planning was never my hot spot! We did change the goal posts in mid-flight (adding a sail, loo, etc, and stretching her from  a planned 16ft to almost 27ft to get everything in, but hey we did get there!), and on the 20th July 2020 we took her for a steam and sail on Windermere with a cameraman (Roger Heise from the SBA) on hand to record her 2nd trip under sail (thank you Roger).

Notes on the Steam Bit

Before I inflict an album of sailing photos on you, a couple of notes on the steam side, especially for Leak Compound builders….

We had been suffering with a loud knock through most of last year, and despite my efforts to engineer it out over the winter it announced its presence on launching about a month back – very disappointing. We narrowed this down to the LP slideways/”small end” connecting rod bearing. Inspection showed there was too much clearance in the crosshead/slideway and a few thou of wear and some galling on the crosshead pin.

So I re-machined the slide-way cover plates to close up the clearances and made a new pin – full of optimism we fired her up again to see (hear) no difference at all – very, very disappointing.

The galling suggested a lubrication problem. You might remember that we have a lubricator which has a separate pump for each bearing. The design for the engine means that a single feed to the top of each connecting rod has to deliver oil both to the crosshead slideways and to the small end (via a t-junction in the rod). My conclusion was that this results in most (all?) the oil leaving via the crosshead, as there is a lot more space there, leaving the small-end pin without sufficient oil. So I replaced the two pumps feeding the HP and LP crossheads with a larger (black-coded) version, delivering 0.1cc/stroke. Miraculously this cured the knock at a stroke! very happy!

We also replaced a leaking clack on the condenser, and had some (but only 6 to 7-inches) vacuum, so it was time to discover if the sail worked….

The sailing log

Grayling and BefurWe left Ferry Nab at about 10:00am and steamed south to pic up Roger from Windermere Marina and the Maltbys (Jill, John and grandchildren) from their boat house.

The Passage North

Then we turned north for a passage to Ambleside. It was a day of light winds (small gusts with moments of near calm blowing from the North). We steamed to just north of Belle Island/Bowness Bay, and then raised the sail and attempted to “beat” upwind…

Befur performed well, managing to claw her way into wind despite our rather poor sail handing (sailing friends are asked to cut us some slack as complete beginners when looking at these pictures, please).

(Larger versions of the images in the slide shows, are also included at the foot of this post…)

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In the interests of keeping the flotilla together, we fired up the boiler to catch up with the others and steamed the rest of the way to the YHA pier at Ambleside for a welcome lunch and coffee…. Does it always rain in the North Basin of Windermere?

The trip south

We steamed off the pier to get off the lee shore, and set to on running back to Bowness with a slightly stronger wind – again she seemed to perform well, although we seem to be reefed down to 5 panels in all the pictures – you could even hear the wash from the bow and stern at some points  – high performance stuff…. Once in the lee of Belle Island at Bowness we steam/sailed the last half mile to Ferry Nab, and Roger’s provided bubbly – we were all very happy… (sorry about the fenders, we are really just not posh enough for the Winermere crew!)

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A snatch of Video

Finally a few seconds of us attempting to tack upwind, with apposite commentary from Roger!

…and thank you all

Thanks to everyone (friends, SBA Members, JRA members and suppliers) who have helped us on the journey to 2020, with generous advice, support, practical help (work), equipment, and good humour)  – and thank you to Louise for allowing me the time (and money) for us to do this and her ever more skilful work as a seamstress, with cushions, beds, covers and that beautiful sail!…

Pictures in full size

Click to enlarge…

Steamboat Crankshafts – Lessons & Manufacture Pt#2

This post continues/concludes the story of manufacturing a new crank for Befur from the last post.

Here we can see the re-assembled engine with new crank. We are still to install all the ancillaries (reversing gear, lubrication, condenser and feed/air pump & alternator drive.)

It took 6-man days from receiving the crank back from the grinders to reach this stage.

Once we have tested it on air, we will reinstall it on the boat and undertake this year’s boiler test and check all is as it should be.

Machining Crank Pins

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Steamboat Crankshafts – Lessons & Manufacture Pt#1

Introduction

Those of you who have been following Befur’s progress will know that our first year in the water was marred by the failure of the crankshaft in the Leak Compound engine I built.

This post deals with the manufacture of a replacement, and the results of my research/experience into the approaches to building cranks for “small” (<20HP) marine steam plants.

Methods of Manufacture

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When a broken crank is good news!

Well we got Befur’s engine back into the workshop, and stripped it down to see if we could locate the source of the knocking we have been suffering all season.

Befur’s Engine ready to be stripped.

On lifting the crank out it looked perfect, and did not have any obvious loose or moving joints My heart sank, as this was really my only theory on what was wrong. Continue reading

“Final” Notes on other potential issues

Having “finished” and tested my engine there were a final set of issues that I suggest you keep an eye on:

  • Piston Rod Lubrication Fitting Clash: The drawings show the small-end and cross head lubrication is achieved via drillings at the  top of the piston rods. There is no indication of how oil is delivered to these drillings. I have arranged this using small-bore flexible nylon tube and push fittings. I installed a small elbow into the feed hole to allow the push fittings to point between the bores. However, space is very limited here, being close under the lower cylinder covers and stuffing box glands. When I packed the glands I found that as these sat slightly lower they clashed with the oil feeds at TDC. I can see no way to move the oil feeds. So I resorted to machining away some of the bolting flange of the stuffing-box glands next to the columns. This has worked, but clearances here are tight.
  • Air Pump Drain Modification: the drawings show a simple drain plug screwed into the bottom of the air pump body. In my design of pump drives this is hard to reach, and having a circulating pump exhausting into the condenser, you can get into the situation where the condenser becomes full of condensate if the main engine/air pump is not running. So I have brought this drain out to a simple taper cock. This just makes things a bit easier.
  • Pinning the Drop Arms: During early testing I found the drop arms had a tendency to slip on the weighshaft. So I installed small taper pins to secure them.
  • Reversing Lever Clash: This was just me not spotting a problem earlier. I fitted the weighshaft at the top of the column position. On final installation I discovered the level collides with the exhaust pipe in full-ahead. Just keep an eye open. 🙂

Continue reading

Relief Vales and Drain Cocks

An experiment – Steam Operated Combined Drains & Relief

Much earlier in the process I baulked at drilling the cylinder castings for the cylinder drain cocks because they looked hard to drill with out risking damage to some rather expensive castings. Moreover, previous experience with manual cylinder drain cocks on the loco had been poor (leaky, difficult linkages etc.) and on the steam launch most people seem to opt for 4 manually operated cocks which involves a deal of “faffing” in use. Continue reading

A fix for the Air Pump

So, following some communication with the steam boating forum we are all agreed that the Edwards Air Pump as drawn is missing  anything to hold the valve-plate in place, or seal its contact with the pump body. This means that:

  1. The whole valve tends to move up and down with the piston rod, (and I think this needs to be a “good” fit to prevent leaking round the pump-rod, so this is unavoidable).
  2. There is nothing to seal the lower valve plate (the one with the holes) where it sits on the ledge of the pump body…

So, my solution is to:

  1. fit a gasket under the valve plate
  2. make and fit a nylon block to hold the plate down – made 10 thou too long, so that the top cover provides some “squishing pressure”

As other members suggested this may help pump performance by removing “deadspace” (but it is beyond the valves so I am not sure if this is correct), and secondly it needed to be made in a way that ensured the outlet port is not cut-off if the block rotates; so, as can be seen in the pics below, I have made it with an exhaust annulus and internal ports to the valve chamber cut in the bottom…

I think this approach will also prevent the valve opening too far….. a test in the kitchen sink proves that it all works!

Here are some pics of the block and completed pump assembly.

air pump stuffing block in situ

air pump stuffing block in situ

air pump valve chest stuffing block

air pump valve chest stuffing block

air pump valve chest stuffing block

air pump valve chest stuffing block

Don’t think the air pump will work

I think there is a problem with the air pump design/drawings…

This looks like it’s not a problem with the drawings, so much as an oversight in the design…

The outlet flap valve assembly is not fixed/located by anything vertically within the outlet chamber… neither is the lower valve plate – part 3 on P20 of the book – (the one with the holes)  sealed against the lip it rests on above the cylinder….so (as I noticed when I completed a trial assembly) the whole valve (both plates and the rubber washer) move up and down with the piston rod, and even if the vacuum held it down, I feel sure any hard won pressure difference would be lost as the air leaked back into the pump round and under the valve plate.

My current plan is to make a nylon “block” which is a light push fit in the outlet chamber, has “ports” to let the air-water out to the  delivery port, and is slightly longer than the available space, so that when the top cover is fitted it will press the lower valve plate down onto a gasket I am fitting under the valve plate….

does anyone have any better ideas/opinions? am I missing something?

The Impulse Valve (Simpling Valve)

I have puzzled over the drawings of the Impulse Valve for a year or more, and spoken to others who can make no sense of it.

Well finally last week while mulling the design over with a friend, he (I think) correctly fathomed how it is meant to be built and operate…

As drawn there appears to be a plunger in a tube which is operated by a press button. There appears to be no way that this would operate, as it would just admit HP steam to the chamber formed between this plunger and the end of the valve body….

The explanation is that this plunger is in fact a tube! Thus when depressed the steam is admitted to the end of the valve assembly, and then passes down the tube to the valve chest/cylinder. There are hints in the drawing that this is the game, but some of the views are incorrectly drawn which leads to the confusion – and actually I am not even sure it could be reliably constructed as drawn.

I think it would still be hard to make this valve steam tight, but in operation this might not be a practical problem…. Thanks to Neil Davis for figuring this out!

*Simpling or Impulse

In the ME words, Mr. Leak complains that many people incorrectly describe the Impulse Valve as a “Simpling Valve”, and he argues that this is wrong as it does not make the engine run as a simple (which is true) but just introduces a HP steam feed into the LP valve chamber to push the engine off HP TDC if it stops there.

He’s right in the description of what it does, but knowledgeable friends of mine tell me that within the road steam community (Traction Engines) these valves on compounds are always known as “Simpling Valves”… so maybe we can continue to use the term…