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spitfire Joined: 22/04/2008 Location: Camborne View Profile View Posts View Personal Album View Personal Files View all Photos Send Private Message |
Why is this?
Posted: 11/06/2012 19:01:04 Reply | Quote Thrutch wrote: I am still thinking about surface features functioning on the surface, without an underground relevance together with earlier ideas in this thread. You would want a clear view of the pump rods at all times possible, not upset by bright sunrise or sunset (I know pumps worked at night too!) and you would want to take advantage of or avoid certain weather conditions. Better take a look, when I have time, at some Derbyshire engine houses now. There is no gain at all for the driver to see the rods, most of the time the view would be obscured by condensing steam misting up the window from the outside anyway -- spitfire IP: 86.175.19.204 |
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Thrutch Joined: 16/02/2009 View Profile View Posts View Personal Album View Personal Files View all Photos Send Private Message |
Why is this?
Posted: 11/06/2012 23:32:33 Reply | Quote To Trwillan - you need to see what is happening on both sides of the engine/pump sysytem in order to prevent "trouble" developing. A Cornish engine has very large forces acting on each end of the beam and has nothing to stop it over-stroking except water in the pumps and a cushion of steam on the piston (if the water is there and the valves are manipulated/operating correctly to provide the steam where needed). Communication between outside and inside engine house would be another factor. To Spitfire - what "window"? As far as I know there would not be the luxury of glass in that situation. Steam from the condenser tank and hot well would be minimal. To both - why put such a large opening as this in a bob wall if it was not essential? With respect, I suggest that, if you have not already done so, you take an opportunity to see a Cornish type engine being started and in operation. I added my contribution to this thread to broaden the considerations being made in it. The focus seemed to be mainly on connections with underground work and workings when the design and orientation of surface buildings and machinery may have less to do with this and more to do with effective functioning - on the surface. IP: 86.145.178.42 |
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Trewillan Joined: 21/02/2012 View Profile View Posts View Personal Album View Personal Files View all Photos Send Private Message |
Why is this?
Posted: 12/06/2012 08:33:32 Reply | Quote Thrutch wrote: To both - why put such a large opening as this in a bob wall if it was not essential? I thought the large openings in the bob wall were provided to allow installation of the engine, particulary the cylinder and the beam. Don't follow how you can "see" a force on pump rods, or how this could be different to what is happening at the indoor end. Stroke is limited by the length of the engine cylinder anyway. IP: 2.97.0.182 |
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Alasdair Neill Joined: 10/12/2008 View Profile View Posts View Personal Album View Personal Files View all Photos Send Private Message |
Why is this?
Posted: 12/06/2012 09:36:00 Reply | Quote I tend to think that for lode mining the surface layouts were largely influenced by underground layouts, unless there were over riding surface considerations such as steep ground. Pre rock drill days engine shafts were more often than not sunk following the dip of the lode (perhaps with a vertical section near surface) as this would reduce the capital cost & time of extensive crosscutting. Of course there are exceptions, usually in cases of large profitable mines where as greater depth was reached the expense of a vertical shaft to reduce working costs was justified. Consols, United, & Tresavean are cases in point. The shafts therefore tended to be aligned to the strike of the lode they were sunk on, & I think you will then find practically all pumping engine houses were planned on or at right angles to that alignment. With vertical shafts using Cornish engines sunk in rock drill days, eg Robinson's Cooks and Taylors, these would almost certainly have been planned around crosscuts driven at right angles to the lodes. Coming more up to date, what was the alignment of the surface arrangements at the modern shafts at Wheal Jane & Mount Wellington? Easy to check, but I would make a guess these would also be related to lode geometry. Google Earth - it appears that the UK orientation is to True North, about 1.5E of GN in N Wales. IP: 46.60.252.96 |
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Trewillan Joined: 21/02/2012 View Profile View Posts View Personal Album View Personal Files View all Photos Send Private Message |
Why is this?
Posted: 12/06/2012 09:54:20 Reply | Quote Alasdair Neill wrote: Coming more up to date, what was the alignment of the surface arrangements at the modern shafts at Wheal Jane & Mount Wellington? Easy to check, but I would make a guess these would also be related to lode geometry. Were the winder houses at Wheal Jane at 90 degrees to each other? No idea how that relates to the lodes. Thanks for the info on orientation of Google Earth, I knew it would be there somewhere. IP: 2.97.0.182 |
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exspelio Joined: 02/05/2012 Location: peak district View Profile View Posts View Personal Album View Personal Files View all Photos Send Private Message |
Why is this?
Posted: 12/06/2012 11:50:27 Reply | Quote Surely engine houses would be built significantly after the initial shaft was sunk? pumping would not be needed until the water level was reached. I appreciate that pumping and man engine shafts where sunk when required and deemed worth it but the underground layout would have been well established before this. Engine houses would be more of an "add on" rather than the start of the mine. IP: 87.127.158.157 |
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Thrutch Joined: 16/02/2009 View Profile View Posts View Personal Album View Personal Files View all Photos Send Private Message |
Why is this?
Posted: 12/06/2012 12:00:05 Reply | Quote The opening in the Bob wall would not allow entry of the cylinder and why pass beam through it when you want that on top? Building a large opening in the strongest wall of the engine house, directly below the highest load point has to be for a purpose - observation and communication. The engine driver needs to know what is happening with the pumps - by observing the behaviour of the rods, by communicating with other workers. Vital of course too during maintenance work when the rods need to be lifted or lowered in stages, the engine moved at less than full stroke. Timing valve movements is best judged by watching the pump side, rather than a difficult view of the engine. The stroke of the engine is not limited by the length of the cylinder, except at a time of total disaster when the piston tries to punch a hole through the top or bottom of it. Some protection might be afforded by wings on the beam meeting with wooden spring beams but again, this is an extreme and destructive scenario. The engine I am involved with is not large by Mine standards - 50" bore, 9'6" stroke, beam 33' long weight 27 tons. Plunger pump lifting around 4tons water/stroke. Plunger 15tons + ballast. Force on the piston over 30tons steam pressure only, over 50 with vacuum. All very quiet, very innocuous but if a "trouble" did arise it, with that lot in motion, it would be very quick and very dramatic. Starting a Cornish engine is done by hand control of the valves (you can find a description on the 'net). The engine continues to be controlled by hand until a steady vacuum is established under the piston (and the whole engine/pump system is balanced and operating smoothly). Further adjustments are needed while in operation according to changes in running conditions. Stopping the engine is again controlled by hand. IP: 86.145.178.42 |
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spitfire Joined: 22/04/2008 Location: Camborne View Profile View Posts View Personal Album View Personal Files View all Photos Send Private Message |
Why is this?
Posted: 12/06/2012 14:32:25 Reply | Quote Thrutch wrote: To Trwillan - you need to see what is happening on both sides of the engine/pump sysytem in order to prevent "trouble" developing. A Cornish engine has very large forces acting on each end of the beam and has nothing to stop it over-stroking except water in the pumps and a cushion of steam on the piston (if the water is there and the valves are manipulated/operating correctly to provide the steam where needed). Communication between outside and inside engine house would be another factor. To Spitfire - what "window"? As far as I know there would not be the luxury of glass in that situation. Steam from the condenser tank and hot well would be minimal. To both - why put such a large opening as this in a bob wall if it was not essential? With respect, I suggest that, if you have not already done so, you take an opportunity to see a Cornish type engine being started and in operation. I added my contribution to this thread to broaden the considerations being made in it. The focus seemed to be mainly on connections with underground work and workings when the design and orientation of surface buildings and machinery may have less to do with this and more to do with effective functioning - on the surface. The cylinder and bob came into the engine house at the rear .known as the cylinder opening. The window I was referring to was in the plug door below the bob wall and behind the condenser. Believe you me, on a cold winters day the steam would be coming from the hotwell in clouds -- spitfire IP: 86.175.19.194 |
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Trewillan Joined: 21/02/2012 View Profile View Posts View Personal Album View Personal Files View all Photos Send Private Message |
Why is this?
Posted: 12/06/2012 15:05:04 Reply | Quote Sorry "Thrutch", still don't understand why you would need to see the pump rods. Jack Trounson's book gives a detailed account of how the beam was installed, in through an opening, the outdoor end lifted and moved over the bob wall, finally lowering the beam onto the bearings. I'll try to find my copy and give the proper title, its well worth reading. Cylinders must have been installed after construction of the engine house, so again must have been brought in through an opening. There wouldn't be a point load on the lower opening in the bob wall, its well below the bearings, and most have a brick arch don't they? Would this opening actually be visible from the driver's position? As you say, stroke of the engine can't be greater than the piston stroke. Weren't engines usually run at full stroke with the strokes-per-minute varied depending on reqiored output from the pumps? Engine started manually, as you describe, then automatic operation of valve gear. IP: 2.97.0.182 |
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spitfire Joined: 22/04/2008 Location: Camborne View Profile View Posts View Personal Album View Personal Files View all Photos Send Private Message |
Why is this?
Posted: 12/06/2012 15:43:39 Reply | Quote Another point is that the driver would not be able to tell if the engine was over stroking by watching the pump rods. The indoor nose of the bob was fitted with catch-wings and they would tap on the spring beams to warn the driver of over-stroking. -- spitfire IP: 86.175.19.194 |
JR Joined: 07/03/2008 Location: Lurking near Hereford View Profile View Posts View Personal Album View Personal Files View all Photos Send Private Message |
Why is this?
Posted: 12/06/2012 20:48:57 Reply | Quote I may be wrong but it was my belief that the engine house was an integral part of a Cornish pumping engine, particularly the deep mines where the forces involved would be immense. My question then is, was the house ever built around the cylinder? -- The voices tell to write this stuff IP: 95.147.195.33 |
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scooptram Joined: 22/05/2007 Location: Camborne Cornwall View Profile View Posts View Personal Album View Personal Files View all Photos Send Private Message |
Why is this?
Posted: 12/06/2012 21:04:10 Reply | Quote there are a few houses built around the cylinder but this was mainly after engine house fires ,theres a good pic of this in one of trounsens books just the bob wall standing .the hole in the bob wall was so the engine driver could see the hot well and oil the linkages. the cornish pumping engine never pumped water! it just returned the rods to the top of the stroke gravity done the work -- mind that rock OUCH IP: 86.137.61.155 |
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Trewillan Joined: 21/02/2012 View Profile View Posts View Personal Album View Personal Files View all Photos Send Private Message |
Why is this?
Posted: 12/06/2012 23:00:57 Reply | Quote JR wrote: I may be wrong but it was my belief that the engine house was an integral part of a Cornish pumping engine, particularly the deep mines where the forces involved would be immense. My question then is, was the house ever built around the cylinder? The force from the beam is all downwards on the bob wall. The cylinder is bolted down to a massive stone base. Those are the important bits. All other walls and the roof are basically for weather protection. The building also supports the floors which are needed for access to the working parts of the engine. IP: 2.97.0.182 |
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Thrutch Joined: 16/02/2009 View Profile View Posts View Personal Album View Personal Files View all Photos Send Private Message |
Why is this?
Posted: 13/06/2012 09:51:44 Reply | Quote Picking up on some previous points: The engine house was indeed an integral part of a Cornish engine. Bob wall and engine base aside there had to be fixing points for the parallelogram motion. Some amazing fitting and aligning work done. Doors were big enough to allow entry of engine parts, including cylinder but looking through photographs some engine houses were built around the engine. I would very much like to see the old account of putting the beam into position. Why would the engine driver need to see the hot well (through a purpose built hole and oil which linkages from there?). While a large proportion of the load from the beam bearings would be carried down the sides of the window below the beam that is still a very large hole to put in a load bearing wall. It is the size of a very large door and gives the engine driver a good view of what is happening at the other end of the beam - essential for operating the engine/pump system. There is a clearer view of engine stroking at the pump rods than looking through through the controls, sharply upwards for a restricted sight of the piston rod. There is no mechanical means of restricting stroke (as, for example a crank would do on an engine fitted with a flywheel). Hearing the catch wings on the beam tapping (how hard is tap?) would have me expecting instant action from the driver or me legging it outside fast before something came crashing down. Tapping comes a bit too late, better control the stroke before that. I do not think the catch wings were a device fitted for monitoring purposes, rather more for maintenance and emergencies. IP: 86.145.178.42 |
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spitfire Joined: 22/04/2008 Location: Camborne View Profile View Posts View Personal Album View Personal Files View all Photos Send Private Message |
Why is this?
Posted: 13/06/2012 10:40:44 Reply | Quote Thrutch wrote: Picking up on some previous points: The engine house was indeed an integral part of a Cornish engine. Bob wall and engine base aside there had to be fixing points for the parallelogram motion. Some amazing fitting and aligning work done. Doors were big enough to allow entry of engine parts, including cylinder but looking through photographs some engine houses were built around the engine. I would very much like to see the old account of putting the beam into position. Why would the engine driver need to see the hot well (through a purpose built hole and oil which linkages from there?). While a large proportion of the load from the beam bearings would be carried down the sides of the window below the beam that is still a very large hole to put in a load bearing wall. It is the size of a very large door and gives the engine driver a good view of what is happening at the other end of the beam - essential for operating the engine/pump system. There is a clearer view of engine stroking at the pump rods than looking through through the controls, sharply upwards for a restricted sight of the piston rod. There is no mechanical means of restricting stroke (as, for example a crank would do on an engine fitted with a flywheel). Hearing the catch wings on the beam tapping (how hard is tap?) would have me expecting instant action from the driver or me legging it outside fast before something came crashing down. Tapping comes a bit too late, better control the stroke before that. I do not think the catch wings were a device fitted for monitoring purposes, rather more for maintenance and emergencies. I don't understand any of that. I'm fortunate enough to remember these engines working on the mine. No engine houese were built around the engine. The beam was passed through the cylinder door at the rear of the house and winched into position. The bolts for the bearings ran through the bob wall and were about 25 feet long depending of course on the size of the engine. -- spitfire IP: 86.175.120.50 |
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Trewillan Joined: 21/02/2012 View Profile View Posts View Personal Album View Personal Files View all Photos Send Private Message |
Why is this?
Posted: 13/06/2012 12:47:56 Reply | Quote spitfire wrote: I don't understand any of that. I'm fortunate enough to remember these engines working on the mine. No engine houese were built around the engine. The beam was passed through the cylinder door at the rear of the house and winched into position. The bolts for the bearings ran through the bob wall and were about 25 feet long depending of course on the size of the engine. No, I don't understand much of that either. Regarding the parallel motion, I thought that was all mounted off the beam, with no connection required to the structure of the engine house. I have seen pictures of small portable engines in use for prospecting or shaft-sinking, effectively skid-mounted and didn't require an engine house. Whether any of these were beam engines I can't remember. I'll check the Trounson-Bullen picture books. I have definitely seen smaller beam engines with the beam pivoting on an iron frame instead of a masonry bob wall, similar in appearance to the oil-field "nodding donkeys". I'll also get the title of Jack Trounson's small book. Apart from the account of erecting the beam, this has a story about an engine driver asleep and not aware that the beam is hitting the catch wings! IP: 2.97.0.182 |
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Thrutch Joined: 16/02/2009 View Profile View Posts View Personal Album View Personal Files View all Photos Send Private Message |
Why is this?
Posted: 13/06/2012 18:39:24 Reply | Quote I am sorry that some have failed to understand my last post - I believe that it is clear enough but to make it clearer still I could have linked each part of it as a response to a previous post. I am a member of a team which maintains and runs a Cornish type engine and I am confident that the information I have posted here is accurate. If any aditnow members are ever in my area I would be happy to show then around the engine/pump/boilerhouse installation, on one of our open days or by appointment. I could also direct them to other related engine house remains, mines and other sites in the locality. With the wealth of material available I am a little surprised by some of the categorical statements that have been made here, which are in reality, totally inaccurate. IP: 86.145.178.42 |
Morlock Joined: 31/07/2008 View Profile View Posts View Personal Album View Personal Files View all Photos Send Private Message |
Why is this?
Posted: 13/06/2012 21:40:37 Reply | Quote Never taken much notice before but assume the parallel link motion needs to be anchored to operate? http://en.wikipedia.org/wiki/Parallel_motion IP: 86.25.23.30 |
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Alasdair Neill Joined: 10/12/2008 View Profile View Posts View Personal Album View Personal Files View all Photos Send Private Message |
Why is this?
Posted: 14/06/2012 09:13:27 Reply | Quote Checked Mount Wellington/Wheal Jane Wheal Jane main shaft surface arrangements were planned to the lode orientation, with the winders/headframes at 90 degrees to each other. Mount Wellington winder/headfame was on an north-south orientation, different from the lode orientation. IP: 46.60.252.77 |
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spitfire Joined: 22/04/2008 Location: Camborne View Profile View Posts View Personal Album View Personal Files View all Photos Send Private Message |
Why is this?
Posted: 14/06/2012 09:59:11 Reply | Quote Thrutch wrote: I am sorry that some have failed to understand my last post - I believe that it is clear enough but to make it clearer still I could have linked each part of it as a response to a previous post. I am a member of a team which maintains and runs a Cornish type engine and I am confident that the information I have posted here is accurate. If any aditnow members are ever in my area I would be happy to show then around the engine/pump/boilerhouse installation, on one of our open days or by appointment. I could also direct them to other related engine house remains, mines and other sites in the locality. With the wealth of material available I am a little surprised by some of the categorical statements that have been made here, which are in reality, totally inaccurate. I assume you are talking about a waterwoks engine, which is entirely a different mode of construction. I am not going to continue with this, because regarding mine engines you haven't a clue of what you're talking about -- spitfire IP: 86.175.20.26 |
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