I've decided that at this point it would be useful to build the set of bending rolls that I bought the kit for back in March 2006! These will make it much easier to roll up the boiler cleading and also the curved cab roof. I've made a start on them and hopefully they shouldn't take too long to complete.
Yesterday I took Helen to the 2½" running day at the North West Leicester Society's track at Whitwick (Nr Coalville) and had a thoroughly enjoyable day. I haven't had time to do anything to the loco apart from fitting some cork insulation to the firebox. I've been busy instead making the bending rolls and a driving truck. The rolls are nearly finished and I got the driving trolley running the night before the running day! I'll post a bit about the trolley in a seperate section later as it may be of interest to anyone wanting a simple 4 wheel trolley.
One thing I did manage to do to Helen was make a sleeve to reduce the diameter of the blast nozzle slightly to see if that would improve the steaming at all.
It was a beautiful day at Whitwick and I actually got a bit sunburnt! What a pleasant change from all the rain!
I managed half a dozen laps with Helen before losing the fire so came off for a tea break. The reduced blast nozzle seems to definitely improve the steaming with the coal I am using and a quick glance at the fire on a couple of occasions whilst hurtling around the track showed it to be burning well. The safety valves were also gently feathering most of the time which is a good sign. The only problem now seems to be that the coal burns away very quickly and I think I'll get some anthracite and try mixing some of that in with the steam coal. The anthracite is a lot harder coal and burns more slowly. Hopefully this will extend the time between firings. I'm still following the routine of stoking up the fire, doing a couple of laps, and then stopping to build up the fire again. Ideally, it would be best to fire on the run but it's not that easy!
After a few cups of tea and a cake I gave a fellow member of the Association (Tony Durnsford) a hand with his newly acquired 'King George V' which is a full four cylinder design by Henry Greenly I believe. Tony was struggling to get the fire going but with a good raking out and a lend of my blower (which is more powerful than his) we managed to get a good fire going. Unfortunately he lost it again after getting on to the track so we ajourned for more tea! I think the coal that Tony is using is much too small for the loco. He's using the smallest size (grains) and it just burns away too quickly. The firebox on the King is very similar in size to Helen's and I use the next size up (Beans) I've suggested that he try some bigger lumps next time.
Tony decided it would be a good idea to drop the grate and start from afresh. How to do this took a bit of fathoming out but we managed eventually. The design of the grate and ashpan is not very clever and makes the job very difficult. The 'ashpan' is just a flat plate held up with a couple of pins and is difficult to drop due to pipes and the lubricator drive getting in the way. The grate is held up by three bits of vertical steel soldered to the plate and the only way we could put it all back together was by lying the loco on it's side. I've suggested that Tony make a new ashpan which is easier to remove and replace! After all this palarvour Tony decided to call it a day so I went back to running Helen again.
*( Note added 13/08/08 - The king mentioned above is actually a 'Kingette' described by LBSC in Model Engineer in the early 30's. Although there is no proof as yet, I believe this could be the same loco in Brian Hollingsworth's book on LBSC in which a photograph appears of Cyril Grose (responsible for a lot of the photos in the Live Steam Notes in ME) driving a Kingette on LBSC's Polar Route)*
I decided to try and start a new fire without dropping the remains of the old one and had a bit of a struggle to get a decent fire going. Managed it eventually though and did about 10 laps in all. I persuaded brother Mick to have a go as he's never driven a loco before and he did a lap very cautiously. I noticed on the last few laps I did that the valves were getting a bit tight (you can tell by the sound of the exhaust). The loco was very hot after all that running so I decided to call it a day before any damage was done.
All in all another successful day. Despite the track being a bit rough and some very tight curves I had no problem staying on the track, both Helen and the new driving trolley (minus brakes - didn't have time to fit them!) holding the road very well.
Helen and myself at speed!
Brother Mick taking it easy!
Not much to report this time on Helen as I've been busy on other things. The bending rolls are now finished and ready to use (see equipment section) and I've been finishing off the driving trolley. It looks a lot better now my attempts at MIG welding are covered by a coat of paint!
I'm looking into injectors at the moment (see separate section) with a view to making a couple to fit to Helen. The next Rally is on August 5th at Sutton Coldfield MES so I want to try and get the boiler cleading on by then and finish the cab to make her look a bit more presentable.
I've now joined North West Leicester MES so can go and have a run anytime I like which will be great. I want to try and get there for a day next week and have a play with some different coal and different sizes of coal. Hopefully I can find the best combination after a bit of trial and error. It's much easier to do this when you've got the track to yourself and you're not holding other people up all the time!
I didn't manage to get to the track for a run due to lack of time but I did manage to get the two water valves for the injectors made and fitted. I forgot to get some photos of the actual valves as I was making them (I was in a bit of a rush to get them done!) but they are simple plug cock types of valves which require only a quarter turn to turn them on and off. The actual rotating valve bit is made from PTFE driven by a cross pin on the end of the valve stem which engages in a slot in the top of the valve. They are nice and smooth to operate and very easy to turn. The valve body is inside the rear bunker with the outlet extending through the bottom of the tank and through a hole in the running boards. The actual injectors will fit underneath the running boards.
At the same time as fitting the valves I fitted a pipe through the bottom of the tank which extends to the top of the bunker. The other end has a pipe running to the rear buffer beam for connecting to a water feed from the driving trolley. This enables the water level in the loco tanks to be maintained at a constant level.
While I had the top off the bunker I removed the hand pump and sorted out the valve problem that had been apparent since it was first used. The top supply valve was fine but the ball in the suction valve had far too much lift and was bouncing. The lift was reduced to about 1/32" and the pump now works perfectly.
One last job I managed to do before going to the rally at Little Hay was to fit a floor to the cab to cover the big hole in the bottom!
Injector water valves and cab floor fitted
The rest of the time was spent putting the driving trolley back together, fitting some brakes, and rigging up a water tank to fit on the back.
The rally at Little Hay was very enjoyable with quite a few locos running but I had a bit of a mixed day with Helen. I had a run first thing of about 6 laps but with the small circuit and the number of locos it was all stopping and starting and impossible to get a decent continuous run. However this did give plenty of time for stoking the fire while waiting for the signals to give the all clear! I had a nasty moment early on when Helen came off the rails completely when pulling away at the entrance to the tunnel but this only happened the once. I later learned that David White had also come off in the same place with his little electric loco and the other drivers said they had noticed a problem here.. It turns out that there was a very nasty 'joggle' in the track at this point and you could feel the loco jolt sideways when she passed over this.
The water tank idea worked well and kept the loco tanks full all the time so that was one less thing to worry about! The only snag is that the water bottle is rather high (it's just an ordinary 5 litre container) and makes getting on and off the trolley rather awkward! I'm now looking for a shorter version to alleviate this problem.
Helen with driving trolley and water container on the back
Waiting for a green!
After a liquid lunch at the pub down the road I had another run but this was very disappointing as the front bogie just would not stay on the track and I gave up after a couple of laps. I put it down to the track and decided that the bogie probably needed a bit more weight on it. This was surprising though as I had completed plenty of laps at the NWL track at Whitwick without any problems at all and that track is pretty rough in places. I did wonder if it could be something to do with the fact that Little Hay is aluminium track with a rounded top whereas all the previous runs have been done on square top steel rail? I'm taking Helen to Whitwick on Thursday so I'll see what happens there.
However, after saying all that, another possible cause for the bogie problem appeared. Before the second run I refilled the lubricator but forgot to put the filler cap back on. This is just a length of brass rod turned down at the end to fit the filler pipe. In fact the photo above of Helen in the steaming bay shows the cap on the running board. After the run I realised that it had disappeared and I assumed it had fell off on the track somewhere. When I got Helen home and cleaned her up I had a play with the front bogie and the filler cap fell out! It had obviously rolled off the running board and lodged in the front end somewhere. It is possible that this had restricted the vertical or sideways movement of the bogie and caused the derailing.
Incidentally, I had fitted the cycle speedometer to the driving truck prior to going to Little Hay and this recorded a total distance travelled of 0.64 miles at an average speed of 1.3 mph (due to all the stopping and starting!) with an actual total running time of 28 minutes 10 seconds. This compares to about 1.5 miles done at Rugby and 2.4 miles at Whitwick (both estimated).
A couple of things want looking at now I think. I am not sure the lubricator is supplying enough oil again so I want to check that. There is no evidence of oil around the top of the chimney although my glasses were spattered with oil drops after the run! Also I am not sure the axle pumps are delivering all the water they should do as with the bypass fully closed they seem to struggle to maintain the water level in the boiler. I would have expected the two pumps to easily supply more than the boiler uses. Perhaps one of the valves is not sealing properly.
I went over to Whitwick today and after helping to do a bit of work on the track gave Helen another run. We did about 2 miles around the track and had no problems with the front bogie at all so it may well have been the lubricator cap that had caused the trouble at Little Hay. It was nice to have an uninterupted run and we managed to cruise around at speeds of up to 6mph! Helen will go a lot faster but I'm not pushing it on that track as there quite a few 'umps and ollas'!
Yesterday I had a look at the water pumps and noticed that one of the eccentrics had moved on the axle so that both pumps were on the feed stroke more or less at the same time instead of 180° apart. I managed to get at the securing grub screw by undoing the bolts holding the eccentric strap together and reset the eccentric without too much trouble. On todays run the pumps just about maintained the water level in the boiler but I still don't think they are working properly. More investigation is needed I think. Once the injectors are working though I won't need the pumps anyway (hopefully!).
I had a look at the lubricator as well and that seemed to be working ok. I increased the travel of the operating lever just to be on the safe side and, judging by the amount of oil on my glasses today, it is supplying more oil. I think the valves still get a little tight sometimes but everything seemed ok today.
Just a quick update but not much to report as I've been tied up with other things.
I've taken the boiler off so that I can fit the boiler cleading. Once the boiler is re-fitted I can finish off all the platework i.e. the cab etc.
I also dismantled the steam pipes to the outside cylinders and discovered that the O rings sealing the joints have gone soft and 'gooey' and I think they have been leaking. Obviously the steam temperature is more than the ordinary silicon O rings can withstand so I'm going to have to fit higher temperature versions. These are available but I need to find someone who will supply them in small quantities. The other alternative is to alter the joints to nut and cone type but there's not a lot of room to do this.
I've spent the last two days working on the boiler cleading. This is 0.012" thick hard brass sheet which I obtained from RS components as they were one of the few people who listed such thin brass. The cleading is in two sections, one covering the top of the firebox, and the other the boiler barrel. The firebox section only extends halfway down the firebox to make it easier to fit and is merely a curved sheet rolled to a radius to suit the outside diameter of the firebox wrapper. The 'new' bending rolls were used for this and made a perfect job. The cleading has two holes in the top to clear the safety valves and I found the best way to cut them was to drill a small hole in the centre and then open out to the full diameter with a round needle file. It would be very difficult to drill a full size hole in such thin sheet without making a mess of it.
The firebox cleading is not fastened to the boiler at all and is basically self supporting. It will be held at the cab end by a thin angle fastened to the front of the spectacle plate and at the barrel end by one of the boiler bands.
The barrel section of cleading is a full size tube, again rolled up using the bending rolls. The rolls make the job so easy and the time taken to make them was well spent. The large hole for the dome and the two smaller holes for the boiler clacks were again filed out with needle files. Incidently, the positions of all the holes were marked using a thick paper template which had been wrapped around the boiler and the positions of the bushes marked by rubbing a finger over the top of the bushes leaving an imprint of the bush on the paper. The holes in the paper were then cut out with a sharp knife and checked by refitting the template on the boiler. It's better to use paper first before cutting the brass in case you make a mistake!
The barrel cleading was then clamped around the boiler with copper wire with the joint underneath. The cleading had been deliberately cut slightly long so that the edges overlapped slightly at the joint. The joint was then tacked together with soft solder. The cleading is thus fitted 'semi-permanently' but can be removed if necessary by melting the solder.
The two sections of cleading fitted in place
Next job was the boiler bands. I didn't have any suitable brass strip so finished up cutting 1/8" wide strips from the brass sheet used for the cleading. This was a bit fiddly but I managed it by clamping a steel ruler onto the sheet laid on a flat surface and cutting through the sheet with a sharp knife. This got through several blades as they are rapidly blunted but did the job eventually. Cutting the strips this way ensured that they remained straight and flat. If I had tried cutting them with shears or scissors they would have finished up curved and it would have been very difficult to get them straight again. The edges of the strips were cleaned up with emery paper to remove any burrs etc. The bands turned out very well and are not too 'overscale'.
Three of the bands on the barrel are full length i.e. they go all the way around the boiler but the fourth is made in two bits as it goes on the centreline of the dome. These two 'half' bands were screwed to the cleading at the top with 14BA screws which will be hidden by the dome when fitted. I spent more time rescuing these tiny screws from the floor after I'd dropped them than fitting them! The bottom ends of the bands are held together underneath the barrel by 12BA nuts and bolts put through holes in the ends of the bands after bending the ends at right angles. I did consider fastening little bits of angle to the ends of the bands as often suggested in write-ups but this seemed very fiddly and time consuming. Just bending the ends proved to be perfectly satisfactory and much easier! I did put washers under the bolt heads and the nuts though which probably helped.
The last band on the barrel covers the joint between the two sections of cleading and holds the firebox section in place at the front. The position of this joint had been worked out beforehand so that the band would be in the correct position when fitted!
The two bands on top of the firebox cleading are 'dummies' soft soldered onto the cleading. These short bands were rolled to shape in the bending rolls and secured in position with a turn of thin copper wire before soldering with a touch of very thin multicore solder. The band covering the joint between the two pieces of cleading was also given a touch of solder to stop it moving and uncovering the joint.
Finished cleading with boiler bands fitted
I've also been in touch with James Walker who manufacture a high temperature O ring made from a material called 'Kalrez'. These are able to withstand a temperature of 315° C so may solve the O ring problem. Apparently a company called Brammer act as their distrubutors and there just happens to be a branch in Derby so I'll give them a ring and see if thay can supply some.
I've been in touch with Brammer about the Kalrez O rings and they came back with a price of £10 each!! I decided that this was way too expensive for a one off job so I've had a rethink and machined up two new steam pipes with PTFE sealing rings which should be able to stand the temperature. The rings are threaded onto the ends of the new steam pipes and secured with a thin locknut to prevent them unscrewing when the pipes are rotated to screw them into the cylinders. Hopefully the rings will also expand when they get hot and make a really good seal. They are a good fit when cold anyway but can still slide and rotate in the manifold for assembly.
New steam pipes with PTFE seals
The O ring on the connection to the inside cylinder has also been replaced with a PTFE ring. If the PTFE seals prove to be unsatisfactory I'll make a new manifold with screwed connections to eliminate the seals altogether.
The boiler has been refitted to the chassis and work is continuing on the cab etc. Actually I had to refit the boiler twice as the first time I forgot to fit the grate!! Much railroad esperanto as Curly would say! It's interesting to note that the mild steel grate is showing no signs of burning away and apart from turning blue looks as new.
Previous Page Next Page