Class 10 diesel electric locomotive

The Class 10 loco is an electric powered version of the Diesel shunter. To read more go here.

Prairie 61XX locomotive

A new project started November 2006. To read about it go here

Maid of Kent locomotive

My Maid of Kent in Midland 3P guise in the steaming bay

The Maid of Kent locomotive is one bought second hand in the summer of 2006 and it is built to represent a Midland 3P. The loco had never been steamed before but was already over a decade old maybe two (the boiler was dated 3/69 with the builders name) so some problems were expected . Mechanically the loco seemed quite sound and passed its two times pressure test on the boiler. The Joy valve gear was found to have a couple of bent links that were easily replaced. The first steaming found a few minor steam leaks and one which still baffles me from the steam brake valve that seems to come from behind the brake valve but as it appears to be firmly fixed to the reverser side plate with no visible means of the fixing. I am trusting usage will eventually seal off the leak.

The two fitted injectors are of Reeves supply according to the name on the castings and worked OK albeit they were only really happy with a full head of steam. The steam blower proved to be very efficient. The hand pump in the tender leaked at the delivery hose under pressure so the hose and clamps had to be replaced. Initially the tender water outlet to the injectors also leaked badly as there was no gasket material in between the gauze filter to seal it.

The lubricator, a typical LBSC oscillating pump arrangement, proved not to work as the ratchet was not fixed to the pump shaft firmly and the shaft when it did turn just screwed into the pump operating lever and then jammed the whole shaft rigid, so that all had to be reworked.

The cab roof needed to be modified to provide a sliding hatch arrangement to facilitate driving and view the pressure gauge and glass.

Two track runs were tried and the loco had a rather touchy regulator and wheel slip ( not unusual on a 4-4-0) occurred. The loco appeared not to be balanced on its springs with perhaps too much weight on the front bogie so the driving wheels springing has been firmed to see if it produces an improvement, it certainly causes the loco to sit more level.

The loco now awaits the spring running season 2007 to see if improvements have been achieved.

Update

It has been an eventful commissioning period. On the plus side the rebalancing of the weight seems to have improved adhesion, The lubricator now works too well and it is now on its bottom pin. The access to the cab with its sliding roof is fine and a new piece of pipe and coupling for the hand pump repaired the leak. The brake valve seems to have sealed itself and is acceptable.

Now for the bad bits. The pin holding the reachrod to the joy gear link assembly came out on a run. That caused the links on the left side to get into a solid position and the valve rod was pushed so hard against the front stop it bent. As the crank returned and tried to pull the valve back it pulled the whole gland assembly out of the cylinder block! It turns out to be only a tight push fit. Wonder if that was an LBSC design? Anyway that was all repaired and then I looked at the bracket in which the original pin had come adrift. It was clearly a bodged earlier repair as one of the two fixing screws was broken and it was evidently an old break. A screwed 6 BA rod had been put into the bracket above the broken one and the whole epoxy glued together! The reason for the bodge was soon apparent as it was impossible to get at the lower bolt in the bracket without taking the whole expansion link gear out of the frames. Reluctantly I restored the bodge as best I could.

A test run around the track showed the loco was fine but the timing was slightly out on the repaired cylinder. Enjoying the weather and the runs around the track I had one last run before deciding to pack up ...... one run too many! Another pin in the joy linkage decide to come out and lock up the wheels. Initial examination seemed to show only slight damage but on getting home it was evident that more serious damage had occurred as on of the die block links was loose on the frame that holds all four.

I thought it was a solid fabricated block for the links but after a lot of fiddling and patience the assembly was removed from between the frames and it was evident that each expansion link was pinned and glued with an epoxy type glue!! So much for the engineering integrity of the builder. Its wonderful what paint can hide! It's also a wonder that the links held as long as they did. I suppose it speaks wonders for epoxy resin glue. Needless to say the assembly is now silver soldered together. The up side of having this assembly out is that I can do a proper repair job on the bracket for the reach rod and fit a decently engineered bracket that bolts onto the link assembly properly.

All that remains is to repaint the link assembly, reassemble and retime the cylinders. All other links have now been examined and I cannot find any other suspicious joints that might have had the epoxy resin glue treatment. Also on reassembly the pin that goes through the con rod will be drilled for a 1/32" split pin fitting in one drop link to prevent it coming out again.

Whilst second hand engines that are "good" can no doubt be found but the most careful of examinations can be confounded by an apparent well engineered finish and a good paint job. My lesson on buying a second hand engine is learnt the hard way.

The next update will report on, I hope, a successful recommissioning.

2nd Update

The next run was actually on a ground level track at a GL5 rally. The loco did not run smoothly and it was evident that I had not got the valve timing right and as a result there was a power loss and it was a bit of a so and so to start on a up gradient without a bag full of wheel spin. Only a few laps were done as it was not pleasant to drive under such conditions.

A separate issue was that my ground level driving car for the electric was clearly of no use for a tender loco as I could not reach the controls without the rear driving car bogie tipping up. Also the foot rest was totally wrong as it needed to be on the tender. So a different driving car will need to be built. A borrowed driving car enabled me to run with a temporary foot rest under the tender frames.

The valve gear has now been retimed using the technique of opening the drain cocks and pressurising the boiler to a few psi and checking with a pipe from the drain cocks into water to see when the valve opens by bubbles appearing. Both cylinders needed to be retimed. As with Joy gear the timing changes with axle position the axles were chocked into their running position with spacers between the axlebox keep and the bearing block and the loco raised on its stand for timing and testing. The valve timing was adjusted so the valve opened just a tad before top dead centre to give some advance as this is supposed to give some cushioning effect to the piston as it travels over top dead centre and all my Stephenson valve gear models are timed this way.

The reach rod connection with its bracket onto the curved guides is under some stress as the operation of the sliding blocks in the guides is moving the curved guide frame at a couple of points in the block travel when all that should happen is for the blocks to slide up and down on the radius of the valve rod. The movement is not great but is sufficient to tend to loosen the reach rod bracket bolts. It is not yet clear why this is occurring. Possibility is that the centre lines of the valve spindle and curved guide frame are not in line, not sure as to how this can be checked.

So onto the next steaming to see what progress has been made.

3rd Update

The valve retiming was very successful and the loco ran exceptionally well. All in all a 1 1/2 hour running session was enjoyed but terminated due to a repeat of an earlier problem...... the valve rod gland boss coming out of the cylinder block. The boss which houses the actual stuffing gland is only an interference fit in the cylinder block. I cannot imagine how such an engineered feature could be put in place on a piece of the loco that is subject to heating and cooling and is under pressure. But that is how it has been done. Fortunately no damage ensued.

The "repair" that has been done is to drill and tap 6 BA an angled hole through the cylinder block face into the boss and a 6 BA grub screw loctited in place to prevent outward movement (I hope!). Only running and time will show if this is successful. Given that it is successful the small hole can be filled and it will not readily be in view.

The other "problem" I had was the reach rod bracket moving and apparently under some stress from the movement of the curved guides. This I think has been solved. The problem turned out to be due to the drop links from the sliding blocks rubbing against the curved guides. This was shown up by coating the edges of the curved guides with Spectra blue and the high spots were revealed. There remains the slightest of movement of the curved guides about their fulcrum but there is now no hint of any stiffness that was apparent before as the links rubbed, and there are no high spots showing from the Spectra blue application.

Have I cracked it this time? ..... we shall see.

4th Update

Happily I can record a successful run, indeed a series of runs without mishap. Everything worked as it should and it was a pleasure to drive. So I think the building bugs have all been ironed out although no doubt with use there may be other work required but hopefully this falls into the maintenance catagory.