For the real black fingernail addicts, here are Scotty’s excruciatingly detailed explanations:
First, let me say that Fenrir is really a very simple boat, technically. If you are looking for bow thrusters, inverters, battery banks, heat exchangers, hydraulics, radar and the like , we have none of those. We have not even got an anchor windless though we would like one. (anyone got a spare classic Dutch barge windless?)
The interesting bit is the propulsion system, which Fred Dibnah would have enjoyed. But we will save the best bit till last.
Dealing with the domestic systems first, Fenrir is set up very much like a house on the water. Apart from the Central Heating, which is diesel (which I now know to be very similar to the heating oil supplied to houses with oil fired heating), everything is powered by mains electricity. At previous moorings, we only had a 16A supply which meant you could not have the kettle on while cooking. On the plus-side, we have no gas bottles or burners to contend with, and this did make our Boat Safety inspection much more straight forward.
When purchased, the main living quarters (below deck) had been fitted out nicely, with lots of continental sockets. A job lot of Shuko to 13A square adaptors was one of Skips’s Christmas presents! All brought back to breakers and an RCD in a domestic consumer unit the wheelhouse. But at that stage the previous owners ran out of time or enthusiasm, and the circuit finished in a short flying lead with a Shuko plug on the end, and was completed by a rover reel to the shore. Fortunately we have lots of electricians in our extended family, and we now have extra circuits in the consumer unit and a proper 32A inlet mounted on the superstructure outside. Also, to please Skips, a mains Voltmeter and Ammeter.
Skips and No.1 like a minimalist approach, as you will see later when we look at ships instrumentation. Thus the LV switch panel (no Vetus for us, they also favour a low cost approach – don't ask about my wages) is tucked away in the cupboard housing the consumer unit. Good old fashioned chrome toggle switches are more in keeping with the rest on her engineering anyway – rocker switches are for white plastic boats [Ooooooo! – Skips]
Returning to the mains power side of things, the only other source of mains is a generator. At purchase, this was in the engine room with a flexible exhaust pipe welded on and out through the side. Although a good (expensive) make it was not really boat equipment. It was extremely noisy and fumes leaked into the engine room. Still it ran non stop for most of the crossing from Holland, backed up by my much cheaper one from B&Q. We have now removed it to forecastle and wired up an input plug by it which connects to a two way break before make switch in the switch cupboard.
So when cruising we can have a cup of tea, at the expense of subjecting a bit of the tranquil Thames to noise pollution. Still some of the little white boats are that noisy all the time [He’s at it again! - Skips]
Skips has written up the boiler - all I will add is that it too runs from mains – the pump – just replaced – is a standard CH device but the control system runs off 24V DC and the boat came with an amazing device which is overkill but works and it now tucked away where you can no longer trip over it.
Heat transfer to living quarters is via conventional copper pipe and conventional radiators – lots of them. Last part of the domestics is water. The front hull is the water tank – huge. Skips and I have different opinions – I would put plastic tanks for fresh water and black water down there, making the installation of a flush toilet much easier. Skips likes having one thing on Fenrir which is bigger than average. The mains water supply freezing up may not have helped my cause. Getting a mains water supply has been a recent addition – adding one of the few plastic (watch it! – Skips) bits on the boat. A neat water inlet from Plastimo, using a standard hoselock type fitting. It did blister and hole recently, but was changed without fuss by the nice people at Emsworth chandlers – recommended.
When on tank water we need a pump. When running the one we have is fine. It was a pain just recently because it would run continuously, just when we needed it as the mains supply had frozen up, Much effort to find and fit a new pressure switch only to find it was not the switch, but the small pipe to it that had blocked. Cleaned, reassembled only to find the pipe had split – heartbreaking. Skips had to fix it himself, tee hee, not only got black fingernails, but also wet trousers.
May I just digress for a moment... [Not if it’s about white boats – Skips] ... Some of the photos on the page are quite old, and often go back to when the boat was in Holland or our early days when we were often covered on water, diesel or muck. Everything is much tidier now and we rarely get messy, well not as often as we used to.
Before we finally get to the exciting bit [Sad, isn’t he! – Skips] lets deal with the controls and instrumentation. There isn’t much. One big wheel, nice and original with sticky out handles in classic style. But after you have been hit by one a few times when a passing wave moves the rudder, you understand why people add a ring to the periphery. Fenrir’s wheel is quite directly geared, a little over 3 turns lock to lock, and that turns the rudder 90 degrees to the hull. (As an aside, this too may have been needed to navigate the 22m long lock in Langedijke.) So little correction is needed for normal cruising and beginners, zigzagging is even easier than normal.
The linkage to the rudder is as much blacksmithing as engineering. The wheel turns a cog on which sits a piece of thick bike chain. At floor level this changes to conventional chain which runs over pulleys to get to either side of the inner hull, where steel rod sits in a channel made of U section girder which runs to the stern. Whereupon it translates again to chain which wraps around a quadrant attached to the rudder post. I think it is original and should last another 80 years easy. [Did I mention the word excruciating? – Skips – at least he did not say, no mamby pamby hydraulics like white boats have – Oops – he’s got me at it now]
Back upstairs, it is simplicity itself. No instruments at all. Just a flat wooden shelf. We have a VHF set that will come out when we go tidal. Why no rev counter? – what do we need that for – you can hear our engine. Why no ammeter? – we have no amps (more later). Why no fuel gauge? – we have a dipstick, and use so little fuel anyway it is not a worry. Why no oil pressure gauge? – Ok – I’ll give you that one, but there is an original on the engine. Why no temperature gauge? – well, our problem is the engine runs too cold. What was good, on one journey, was the Sat Nav from the car. It got a sore throat trying to get us out of the river, but when you do not know the river, one wooded section looks just like another.
But we do need to control speed and direction. The original throttle seem to have been a cast iron hand wheel which sat on a vertical tube about knee height by the wheel. The wheel pulled a threaded rod up and down, and this linked to the engine via rods and cable. By the time we got her, the threaded rod had stripped, and in our crowded waterway we did not fancy a system which took some time to wind off the throttle. So we fitted a Morse control, courtesy of eBay and connected it to the old linkage. Gears are controlled manually – very manually. You will see in the photo above a lever by the wheel which looks like a railway signal box lever. Heave it forward, and you go forward, Heave it right back, and you have reverse. Much grating and crashing (and cursing) but it works. Not quite so nice as a Morse based mechanism for doing gentle corrections, but you do feel macho and authentic. Originally I thought it was a crash box – there certainly is a lot of crashing, but the actual gear changing is all done with brake bands, so I have decided that the mechanical noise come mainly from the long heavy linkage.
That’s it! If we do ever do a lot of cruising, then a remote oil pressure and water temperature gauge would be nice.
NOW (wake up at the back), the bit you have all been waiting for, the BRONS. BRONS made a whole range of engines over the years. The EA range was conceived pre-war, initially (in 1935) as a tractor engine in a two cylinder version. Most BRONS engine seem to have been made on a modular basis and you could buy 1, 2, 3 or 4 cylinders depending on the power required. Ours is a two cylinder unit, like the tractor.
Mr. BRONS tells us that the engine was originally sold as a pumping engine, but came back to the factory quite quickly and was turned into the marine version, presumably by putting the big pulley on the front and the simple gearbox on the back.
Technically she is some 4 litres, 36 HP (honest) at 720 rpm. The flywheel is over 3 feet in diameter and weighs some 330Kg. I have never really grasped the difference between power and torque, but if Fenrir has little power, she has lots of torque. (tba) The gearbox is a one to one ratio, so the prop runs at engine speed. Tickover is about 120 rpm, with each firing pulse sounding like a hammer hitting an anvil.
The prop is completely different to the high speed ones you see on nice white boats – caught you there. It is apparently somewhat worn, but not that much.
Part of the engine’s fascination is it’s simplicity and accessibility. It would make a good teaching aid. All the valve gear is exposed, and it goes slow enough to see each valve go up and down. The fuel route is clear, through a (felt – washable) filter to the high pressure pump to injectors sitting by the valve gear. Lubrication of valves, rockers and pushrods is by oilcan prior to starting and every two hours whilst running – al la Fred.
Cooling is by direct intake of river water. She is in fact over cooled, and it would be nice to have a recycling system if one were to cruise a lot. But she is astonishingly economic – about one and a half litres an hour at Thames speeds and does not smoke after start-up. Exhaust is water-cooled and dry and enormous. So cool that it hurt to spend a fortune on lagging to meet Boat Safety requirements when you could put your hand on the exhaust.
The big funny about the BRONS is the starting system. It uses compressed air. Sailors will not be too surprised, and fortunately many lockkeepers are ex-sailors and are kind enough to let us leave the engine running. I still do not quite understand the mechanism, but here is what we do. First make sure your air cylinders have air. I try to use Big Bertha and keep Slim Jim as my absolute reserve, as he sits and hold his 20 bar month in month out. One day I’ll buy him a new glass for his pressure gauge!
Then you heave the engine over by hand with a large steel bar inserted into hole on the flywheel till it reaches a certain magic position. The tear in the flywheel cover (now tidied) suggests someone forgot to take the bar out before doing the next bit! Then you open various valves in a defined order, swing a control lever on the engine and a couple of revs later the engine is running. It’s as easy as that! [Not always! – Skips] If anyone has a service kit for this big Klinger valve I’d love to hear from them.
Next comes the real bit of industrial history. I have not seen exposed belts since I worked in a pottery driven by a steam engine when I was at school (I know that’s rotten English, but I’m an Engineer). After a bit of valve tweaking we are ready to recharge the air cylinder. After a good start we only loose some 2 bar, but if we are cruising I like to have lots in reserve. Get air in the injectors and you have to spin the engine till it is bled out. The BRONS system involves the use of a separate single cylinder reciprocating air compressor driven at approximately engine speed by belt drive. The engine has a pulley on the front and a clutch mechanism to connect and disconnect it from the crankshaft. Up the revs slightly using the high tech slotted wooden wedge under a nut on the throttle linkage, throw the lever and we add a noise like a demented steam railway engine to the harmony. A few minutes later, the cylinder is replenished.
Another throwback on the engine system is the method of lubrication. In the close up of the top of the compressor you will see old fashioned grease caps. The compressor lubrication (including the cylinder bore) uses these and that also took me back to my youth – unscrewing these and filling them up with an old knife.
In the picture of the compressor you will have seen a red conventional compressor lurking. This is our backup, our Plan B. When we went to Holland (mainly) to see the engine run, we were thwarted because there was insufficient air pressure in the cylinders. It is a catch 22 – no air – no engine. No engine – no air. So we are a bit paranoid. Initially I thrashed about trying to find a 20 bar device, but they are just not available other than at astronomic prices. However our dear friend Mr. Positive who finally got the engine running used a conventional compressor and we have found since that now we have the knack, 10 bar is OK. As an aside, he first used some devices called stickstorf or similar, which are for emergency inflation of vehicle tyres and do not seem to be available in the UK. The last bit of reassurance is that the generator is man enough to cope with the startup switch on demand from the compressor.
Almost done. [Good – Skips] You may have realised, but I will confirm, that this engine has no electrics at all. Being diesel it has no ignition, being old it has no electronics, being air-start it has no starter motor. The down side is that it has no generator. And running at 120 rpm or a bit more, fitting one is not an easy job. If Mr. Positive was in England we might have a go at running a long multi V belt around the flywheel and to a car like alternator, but that’s it bit too much fabrication for me. And as the boat is mainly mains powered it is not vital. Not vital I hear you say! [no – that’s snoring you hear - Skips] What about Navigation Lights, you might say [if they had not gone home – Skips]. Our system is basic. One large car battery as a reservoir. The generator powers a battery charger when it is running. Also, the Nav lights are switchable from the battery supply to a domestic lighting transformer, which runs off the mains, i.e. the generator. Simple and adequate for current purposes. Okay, onto the last bit of the jigsaw... [Groan! – Skips]
What better way to finish than with the Gearbox. The funniest thing about this gearbox is that most of the time it spins around with the prop shaft. In the picture it is the bit in between the flywheel and the massive thrust bearing. The gear lever operates the cream painted brake band to change direction (and also moved a thrust collar). I cannot say I fully understand the mechanism, but if you have read this far you must be as daft as me, so as a special treat, enjoy the picture of the cross sectional drawing at the top of the page. When we first got Fenrir she was exactly as shown, and to get to the engine controls you had to clamber over the rotating prop shaft and gearbox. We do now have a simple cover, finished, much to Skips disgust, with fetching paisley design carpet to save my old kneecaps a little...
Heave it right back, and you have reverse. Much grating and crashing (and cursing) but it works. Not quite so nice as a Morse based mechanism for doing gentle corrections, but you do feel macho and authentic. Originally I thought it was a crash box – there certainly is a lot of crashing, but the actual gear changing is all done with brake bands, so I have decided that the mechanical noise come mainly from the long heavy linkage.
