Gibbo675

Hi Johnster, I would go as far as to say copacetic ! Thanks for enlarging my vocabulary, Gibbo.

Hi Chaps, I like both of these renditions very much, the only detail to note is that the trailing truck would likely be of the type that 6256 and 6257 used as the locomotives may well not have had the splayed frames of the earlier pacifics. The 2-10-2 certainly looks like a track straightener and the 4-6-4 looks fast. How about giving the 2-10-2 a cut down cab sheet and a tender with an inset bunker and the 4-6-4 a double chimney (just ignore me Corbs for being overly picky). Gibbo.

Hi There, If John Lennon would have been nearly 80 by now, do you think he would have thought it looked like Harold Lloyd ? Gibbo.

Hi Mike, The primary cause of false readings given by Bulleid reverser scales is that should the oil level in the locking cylinder drop then its ability to hydraulically lock the valve gear into position is lost. The other problem connected with this situation is that the valve gear may jump about while the locomotive is under power giving rise to all sorts of cut off positions either every revolution of the wheels or in a harmonic relative to the revolution of the wheels. Half a pint of steam oil and a nip of the gland nuts sorts them out, but that requires climbing up under the boiler just ahead of the fire box. Gibbo.

Hi Phil, Allow me to dispel some myths, Bulleid valve gear is very difficult to set up but once it is set up it is very easy to retain its setting unless new valve liners are fitted. As for the chains running slack this is partially nonsense as the chains are Morse type chains and when slack they run on the outer ends of the teeth of the sprockets which retains the timing function of the chain. Morse type chains are, or at least were, used for the timing chains of internal combustion for that very reason. I would suggest that 34043 had its sprockets misaligned when the horizontal chain was connected on the setting of the valves. This is quite easy to do as all of the backlash has to be accounted for when connecting the chain. There is also the matter that the valve does not move when cogging the sprockets for four teeth when establishing front dead centre. If this had happened at shopping then the lead function would be in the wrong place and cause the engine to work better "inside out" so to speak. During a frantic all nighter, I once managed to put Tangemere's chain on 180* out of sync and the locomotive did run but was quite loud and struggled to pull its own tender. How we laughed at having to slide around an oily connecting rod to reset it all ! Gibbo.

Hi Mr Shovel, That particular reason hadn't occurred to me but asymmetry is still strange. Cheers, Gibbo.

A Shwerubbery !?!?! Nee !!!

Hi There, How about Harold Lloyd should you be over 80 ? Gibbo.

Hi Neil, I think the beaded splashers are definitely the way to go. It is just the way that railway companies used to waste brass upon such titivation that shews that the locomotive is of its time. As for the boiler band lining I would have to have my eyes form twenty years ago to see well enough to do that standard of work. Gibbo.

Hi RussP, I was appointed works manager of an engineering firm at the age of 28. Once, while out doing some site work involving the hydraulic system on a canal lift bridge, with two of my men both approximately double my age, the waterways chaps decided that it would be funny to spend all day taking the mickey out of the "apprentice". They did this all day and were quite rude about it, but between us we decided to let them get on with it because at the end of the day the job required signing off. At the end of the day they asked the oldest one to sign the job off and were told by him to go and see the boss, they then asked the second oldest and got the same answer. How we all laughed when it turned out the "apprentice " was in charge, they must have laughed even more after I had filed a report about their rudeness toward me bye way of their depot manager. My latest age related carry on involved a 32 year old taking the mickey as if I was a similar age to him for a period of a few months. This stopped quite abruptly one lunch time when he asked how old my daughter is. When I told him that she is 29, he nearly fell of his chair. Gibbo.

Hi LMS, You could try thicker socks ?!?!?! Gibbo.

Hi Johnster, If you think a Lada is tough I have experienced Kamaz trucks. In the late 1980'2 I once worked with two chaps from the Chelnyabinsk Order of Lenin Heavy Truck Production Facility. Gibbo.

Hi Blandford, May I also add that some reverser scales were deliberately falsified to prevent damage to the locomotives due to grandmothers that do not require to be taught how to suck eggs. Gibbo.

Hi David, Tender first on network rail is 45 mph irrespective of whether the tender type is a high sided Stanier or Gresley type to the full width of the cab or a BR standard with inset raves or a low sided GWR or Southern type. This is more to do with the instability of a lightly loaded tenders than for sighting purposes. My experience of working 45407 on the main line at speed is that should you know where the signals are you might cross the cab to look out for them or not, much in the same way that you might do running chimney first. That said crossing the cab is usually done by the driver asking for who ever is sitting on the fireman's seat to look out for the signal at the appropriate moment. The greatest impediment to sighting signals is fog and that counts for what ever form of traction you may wish to mention, think trying to look through a bathroom window glass. The fitting of AWS and latterly TPWS is quite helpful in this respect although not so much back in the days of steam. Gibbo.

Its on the palms of his hands !!!

Hi Titan, No locomotive has snifting valves on its steam circuit but some, although not the Bulleid Pacifics, do have anti vacuum valves fitted. In my view anti vacuum valves are a complete waste of time as they are in no way large enough in area to admit enough air to stop the smoke box gasses being drawn into the valve chests or the cylinders at anything above walking pace, 2-3 mph. Coasting at speed with the regulator shut will draw smoke box gasses and char into the valve chests and cylinders irrespective of cut off, although the longer the cut off the greater the effect. Either full forward or full back gear at speed will certainly not do a locomotive any good in either direction with the regulator open, try putting a car into first gear or even reverse at 60 mph and see how that ends up. However if a locomotive is wound into gear opposite to direction of travel at speed with the regulator closed it will attempt to pump compressed air into the boiler, as you note, sucking the air in through the blast pipe, anti vacuum valves will not be of any help whatsoever in preventing this from happening at speed. Gibbo.

Hi 2968, I think there is two ways to look at the 2% figure, either a misprint for what may be 20% or that it actually was 2% because that is where the crew got a comfortable ride when working down hill. Other than interest value I don't suppose it matters that much. Gibbo.

Hi 2968, I stopped Tangemere after a wrong side vacuum brake failure by the use of compression. The reason I chose to do this over using the independent steam brake was that the steam brake only gives approximately 75% brake force of axle loading whereas using back gear and compression I managed to use the full axle loading of the wheels as a brake force, it pulled the train up without slipping and I only used the steam brake at below 5mph. I achieved control of the braking effect by pumping the regulator. Depending upon the lead figures of the gear and also the type of gear employed some engines go quite well in back gear at speed. Walschearts has fixed lead and with Stepenson's the lead increases the nearer to mid gear it is set, therefore with Walschearts gear the reversed cut off will have to exceed the lead figure before any difference is noted. An 8F in 2% back gear will not be effectively working in compression and would suggest that 20% would be the likely minimum that would have any retarding effect. With Stephenson,s gear the lead and cut off exchange functions when placed in opposite gear to direction of travel which causes some locomotives to run more freely at speed at reduced reversed cutoffs than in the same figure cut off for the direction of travel up to about 5-10% depending upon type. As for stresses induced into the connecting rods, crank pins and motion &c. I would suggest that the greatest problem is coasting at speed with the regulator firmly shut. Gibbo.

Is that where you put your Chinese take-away for when you get peckish ? Gibbo.

Hi Woodenhead, My suspicion is that both members of the crew are old codgers whereas, back in the day their ages would have been separated by approximately twenty years. Another observation is that there is a visual lack of what may be termed 'casual competence' in what they are doing, they are quite obviously deliberately concentrating upon the job in hand. Gibbo.

Hi Jason, I used to fire 76079 left handed while sat on the fireman's seat, BR Stds are good like that ! Gibbo.

Hi Corbs, Have you isolated the pick-ups to the wheels so that you don't get spurious control voltages one way or another ? Gibbo.

Hi Corbs, Dr Porta is your man for top quality advanced steam locomotive engineering. The asymmetric arrangement of two cab doors seems strange though. Gibbo.

Hi Jazzer, That has reminded me of the row of terraced houses at Irwell Vale on the ELR that have bedroom windows at footplate height. A couple in one house got caught out in a "curtains open incident" as the Friday evening dining train coasted down from Rawtenstall one time. I know the driver blew the whistle, whether anyone was put off their dinner I cannot comment. Gibbo.

Hi Niels, I hate to be a spoil sport but the thing is, there is a lot more that just wheel diameter to be considered if you want to go fast. For one thing keeping the front end tight when the mean average piston speed creeps up is quite a trouble. Problems such as cylinder wear (tapering, barrelling, and general increased wear rate), piston head wear, leaking gland packings, cross head wear, ring breakage, ring groove tapering, piston rod wear all have to be factored in. Axle boxes along with the pins and bushes of the rods and motion will take a pounding. Even if the axle boxes are fitted with manganese steel liners this may increase service interval of the axle boxes but may not prevent; loose horn ties, loose horn blocks, frame fractures, fractured or loose frame stretchers even loose cylinders. This is with considering the stress reversals that effect the masses of all reciprocating components which is part of the design criteria that define the sections required to transmit the forces of an engine of a particular speed and power output. A 9F at 30 mph has a mean average piston speed of 13.06 feet per second, at 60mph 26.13 feet/sec and at 90 mph 39.2 feet/sec. Most locomotives have a optimum upper bound operating speed equivalent to one inch of driving wheel per mile per hour with a 25% allowance for maximum operating speed. This figure may rise for short stroke locomotives and also the ratio is improved with larger diameter wheels and short stroke engines. Unfortunately the 9F is somewhat over square with a long stroke and small wheels for fast work having a mean average piston speed of 32.66 feet per second at 75 mph. I do like the 2-8-0, I might bash a Dapol kit now that I have looked at it ! Any questions, do ask. Gibbo.