Michael H. Standart
Member
The Straits of Messina? That figures. Congested waterways are always good for surprises like that. That ferry got lucky. Something as massive as a carrier doesn't stop on a dime.
How Titanic's Engines Sounded
- Thread starter robert s hauser
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Steffen Reichel
Member
Hello Robert.
I will noot join the discussion about crash-stop r anything else.
But I can tell you about sound! Titanic has two reciprocating Steam engines and one steam turbine in the middle.
Well, the steam turbine has a sound like a silent hissing or whistling. This noise is not realy loud, often can be only heared in tthe engine room and the rooms apart, but commonly turbines just whistle silently.
Reciprocating Engines do no sound. What some hears in Locomobiles or locomotives is the sound of the blast-pipe, or exaustor. This part of the engine uses the princible of an ejector. the steam is released by a nossle, and forms a steam jet which eacly fits the walls of the chimney. This will result, that the pressure in the smoke box will descent, because the steam jet drags the surounding air in the smoke box through the chimney! The lower smoke box pressure drags the smoke and exaust gas from the fire box through the boiler tubes into the smoke box, were the steam jet will blow this mix out of the chimney.
This is the typical 'puffing' noise one hear in steam locomotives, rhythmicaly, because the steam jet is formed by the exhaust steam of the engines.
Ships and other stationary boilers do not have the need for this, so in Titanic the stteam of the engines is 'recycled', so there is no steam exhaust, the typical puffing noise is absent.
So flowing and expanding steam has no noise, usuallly a light hissing maybe in the tubes and pipes, but very, very silent. So a triple expansion engine is completely balanced. So if the engine is runnung, there is no mass which might 'hammer' a bearing or ist klicking in the gears. So a reciprocating engine runns complete silent, there is no noise from such engines in Ships, except a steam typical hissing from not complete fitting sealings or suffings. So except a maybe rhythmical hissing from such 'leakages' will no sound be created. There is no hammering, knocking or any other rhythmical 'beating', if completely a stand of technical the reciprocating engines creates no sound. Only from the motion moved air creates a only 'feelable' vibration in the air, nothing else....
So in fact of Titanic, there will be only in engine romm a sound of the whistling turbine, and the hissing of steam in tubes and pipes, and from 'leaking' sealings. Next to the engine rooms, a slight rolling maybe typical, because of the rotating shafts and the very silent whistly of the turbine, but some far, there will be no sound....
Titanic was silently, so there is no hammering of anything, like Diesel ships or knowing decks like aboard Diesel ships. Titanic was silent, smooth and you can consider a nearly 'ghostly' motion....
I will noot join the discussion about crash-stop r anything else.
But I can tell you about sound! Titanic has two reciprocating Steam engines and one steam turbine in the middle.
Well, the steam turbine has a sound like a silent hissing or whistling. This noise is not realy loud, often can be only heared in tthe engine room and the rooms apart, but commonly turbines just whistle silently.
Reciprocating Engines do no sound. What some hears in Locomobiles or locomotives is the sound of the blast-pipe, or exaustor. This part of the engine uses the princible of an ejector. the steam is released by a nossle, and forms a steam jet which eacly fits the walls of the chimney. This will result, that the pressure in the smoke box will descent, because the steam jet drags the surounding air in the smoke box through the chimney! The lower smoke box pressure drags the smoke and exaust gas from the fire box through the boiler tubes into the smoke box, were the steam jet will blow this mix out of the chimney.
This is the typical 'puffing' noise one hear in steam locomotives, rhythmicaly, because the steam jet is formed by the exhaust steam of the engines.
Ships and other stationary boilers do not have the need for this, so in Titanic the stteam of the engines is 'recycled', so there is no steam exhaust, the typical puffing noise is absent.
So flowing and expanding steam has no noise, usuallly a light hissing maybe in the tubes and pipes, but very, very silent. So a triple expansion engine is completely balanced. So if the engine is runnung, there is no mass which might 'hammer' a bearing or ist klicking in the gears. So a reciprocating engine runns complete silent, there is no noise from such engines in Ships, except a steam typical hissing from not complete fitting sealings or suffings. So except a maybe rhythmical hissing from such 'leakages' will no sound be created. There is no hammering, knocking or any other rhythmical 'beating', if completely a stand of technical the reciprocating engines creates no sound. Only from the motion moved air creates a only 'feelable' vibration in the air, nothing else....
So in fact of Titanic, there will be only in engine romm a sound of the whistling turbine, and the hissing of steam in tubes and pipes, and from 'leaking' sealings. Next to the engine rooms, a slight rolling maybe typical, because of the rotating shafts and the very silent whistly of the turbine, but some far, there will be no sound....
Titanic was silently, so there is no hammering of anything, like Diesel ships or knowing decks like aboard Diesel ships. Titanic was silent, smooth and you can consider a nearly 'ghostly' motion....
Samuel Halpern
Member
Yes, the engines did not sound like railway steam locomotives for the reasons cited, however, the engine rooms in these ships were anything but quite. The enormous weights of these 15,000 HP engines reciprocating at up to 75 rpm imposed severe stresses on all parts and imposed great vibrations onto the ship's hull despite the fact that they were balanced on the so called Yarrow, Schlick and Tweedy system. Not only was there noise and heat, but the air was filled with water and oil vapors, and the running of various other steam auxiliary engines such as air pumps, circulating pumps, hotwell pumps, feedwater pumps, refrigerating engines, along with bilge, sanitation, ballast, forced lubrication, and fresh water pumps. The low-pressure turbine produced more of a low-pitched hum sound, not a high-pitched whine or whistle, running only up to about 165 rpm. There were no reduction gears linked to this Parsons’ turbine as it was direct acting on the central propeller shaft. In other parts of the ship the sound of the engines were noticeable as an audible throb felt as a vibration in the hull, the extent of which depended on where you located. When the Titanic’s engines stopped shortly after the collision, many passengers realized something unusual had happened because of the absence of vibration from the engines, not because they felt the collision. Others thought that something happened to the engines or the propelling equipment. “There came what seemed to me nothing more than an extra heave of the engines and a more than usually obvious dancing motion of the mattress on which I sat” — Lawrence Beesley.
Jeremy Lee
Member
Would the sound of the engines be audible from the Grand Staircase, and was the vibration felt on the higher decks? Obviously, the engines would not sound like the modern cruise liners of today so is there anywhere to get a close replication of Titanic's engine sound?
Michael H. Standart
Member
About the only place I can think of where one can get a close replication of the Titanic's engine sound would be a ship with an operating triple expansion engine. There's an old Liberty ship in San Fransisco which get's underway from time to time where you can do just that. Click on S.S. Jeremiah O'Brian for more.
As to whether the engines would have been audible from the Grand Staircase, I would have to give that one a resounding "Maybe." I'm inclined to doubt it, though the vibration might have been noticable depending on what the watch team was up to.
As to whether the engines would have been audible from the Grand Staircase, I would have to give that one a resounding "Maybe." I'm inclined to doubt it, though the vibration might have been noticable depending on what the watch team was up to.
Samuel Halpern
Member
Jeremy asked: "Would the sound of the engines be audible from the Grand Staircase, and was the vibration felt on the higher decks?" Best asnwer to give on this would come from those who were there. Archbald Gracie wrote in his book: "My stateroom was an outside one on Deck C on the starboard quarter, somewhat abaft amidships." ... "I listened intently, but could hear no machinery. There was no mistaking that something wrong had happened, because of the ship stopping and the blowing off steam." Another witness, Jack Thayer, wrote: "I occupied a stateroom adjoining that of my Father and Mother on the port side of C deck ... and was just about to step into bed, when I seemed to sway slightly. I immediately realized that the ship had veered to port as though she had been gently pushed. If I had had a brimful glass of water in my hand not a drop would have been spilled, the shock was so slight. Almost immediately the engines stopped. The sudden quiet was startling and disturbing. Like the subdued quiet in a sleeping car, at stop, after a continuous run." ... "Very shortly the engines started up again--slowly--not with the bright vibration to which we were accustomed, but as though they were tired. After very few revolutions they again stopped."
From the above references, one may conclude that the sound of the ship's machinery when moving could be heard to some degree as far up as Deck C, if not higher, and probably on the staircases as well.
From the above references, one may conclude that the sound of the ship's machinery when moving could be heard to some degree as far up as Deck C, if not higher, and probably on the staircases as well.
Larry Robinson
Member
Survivor Beesley also stated that he went to a washroom and layed his hand on a bathtub to feel if Titanic's engines were vibrating through the metal.
Scott R. Andrews
Guest
Here's a link from a website for a small steamer, "Virginia V", which is propelled by a single three-cylinder triple expansion engine: http://www.virginiav.org/movies.htm
You need to take into account that this engine isn't nearly as large as the engines aboard the Titanic, and runs at higher revolutions. Also, the beat of Titanic's engines would have been a bit different as well because of the four-cylinder triple expansion arrangement employed. Still, with a little imagination, the sounds heard in these AVI clips will give you some idea of the types of sounds heard within the engine room of ships propelled by reciprocating steam engines. It's too bad the website for the Jeremiah O'Brien doesn't have something like this, since her much larger main engine would provide something closer to what the sounds may have been like.
Regards,
Scott Andrews
You need to take into account that this engine isn't nearly as large as the engines aboard the Titanic, and runs at higher revolutions. Also, the beat of Titanic's engines would have been a bit different as well because of the four-cylinder triple expansion arrangement employed. Still, with a little imagination, the sounds heard in these AVI clips will give you some idea of the types of sounds heard within the engine room of ships propelled by reciprocating steam engines. It's too bad the website for the Jeremiah O'Brien doesn't have something like this, since her much larger main engine would provide something closer to what the sounds may have been like.
Regards,
Scott Andrews
Steffen Reichel
Member
Dear Scott,
thanks for this incredible link!
Well, this engine runs quite fast, and this little beast rattles hardly it's cage. So from the point, this eengine does not run that smooth and softly other triple expansion engines will do. So the rattle and clicking noise of the main engine is somewhat unnatural for triple expansion engines, and comonly only if the engine runs at all available power.
I guess, if the enginer might 'pull back' the linkage, so give the engine a little more expansion power rather than appling full pressure and filling mode, the rattle and clicking will be more silent.
Because a clicking and rattling bearing isn't that sound engineers like. Because each click means a know into a bearing, the whole rattle will shake the holds, the shaft bearings, the crank bearings and all other moving parts, thus being very destructive. So most triple cylinder engines were completely balanced, so the cranks were set to an angle of 120°, so that allways a smooth run will be permitted, without any rattle or noise.
So I cannot agree completely, Scott. Most triple expansion engines I saw run without any noise. Usually noise comes only from auxillary engines, like water pumps, air pumps and other little engines which adhere more to the boilers than to the engine itself.
So Titanics engine might have made sound, because of having four cylinders, and having no balanced crank angle, so here a silent rattle or shake might be present at full power, but modern large triple expasion engins with balanced cranks do move in complete silence, and only at full power, when the most destructive boiler power 'blows' the engine, well, then each triple expansion engine might shake and rattle.
But his engineers call 'the beast will rattle the cage' and this is an illusionary speech, because if you do this to long and allways, the constant shake will destroy a bearing (didn't it happen to Titanic? If yes, this might show how destructive such full power actions are!), or knock out the crosshead bearing or crank baring, and then, well then the power of the steam might destroy the whole engine. Cast iron be be shredd into pieces, forged steel will be bend like a simple noodle.
so it is not wise, to do this. One can achive full power even without running at full expansion fillings!
So you only have vibrations, like on the huge icebreaker stettin (http://www.dampf-eisbrecher-stettin.de) if some force 'holds' on the propellers, thus 'trying' to slow down the main shaft, and the engine 'leans' against this force, which will result in a rolling shake or rumor of the crank shaft and main shaft, but this is a vibration coming from the propeller rather than from the engine itself....
So I guess the rattle to public about Titanic felt, was this from the propellor resulting shake, and not the engine itself...
thanks for this incredible link!
Well, this engine runs quite fast, and this little beast rattles hardly it's cage. So from the point, this eengine does not run that smooth and softly other triple expansion engines will do. So the rattle and clicking noise of the main engine is somewhat unnatural for triple expansion engines, and comonly only if the engine runs at all available power.
I guess, if the enginer might 'pull back' the linkage, so give the engine a little more expansion power rather than appling full pressure and filling mode, the rattle and clicking will be more silent.
Because a clicking and rattling bearing isn't that sound engineers like. Because each click means a know into a bearing, the whole rattle will shake the holds, the shaft bearings, the crank bearings and all other moving parts, thus being very destructive. So most triple cylinder engines were completely balanced, so the cranks were set to an angle of 120°, so that allways a smooth run will be permitted, without any rattle or noise.
So I cannot agree completely, Scott. Most triple expansion engines I saw run without any noise. Usually noise comes only from auxillary engines, like water pumps, air pumps and other little engines which adhere more to the boilers than to the engine itself.
So Titanics engine might have made sound, because of having four cylinders, and having no balanced crank angle, so here a silent rattle or shake might be present at full power, but modern large triple expasion engins with balanced cranks do move in complete silence, and only at full power, when the most destructive boiler power 'blows' the engine, well, then each triple expansion engine might shake and rattle.
But his engineers call 'the beast will rattle the cage' and this is an illusionary speech, because if you do this to long and allways, the constant shake will destroy a bearing (didn't it happen to Titanic? If yes, this might show how destructive such full power actions are!), or knock out the crosshead bearing or crank baring, and then, well then the power of the steam might destroy the whole engine. Cast iron be be shredd into pieces, forged steel will be bend like a simple noodle.
so it is not wise, to do this. One can achive full power even without running at full expansion fillings!
So you only have vibrations, like on the huge icebreaker stettin (http://www.dampf-eisbrecher-stettin.de) if some force 'holds' on the propellers, thus 'trying' to slow down the main shaft, and the engine 'leans' against this force, which will result in a rolling shake or rumor of the crank shaft and main shaft, but this is a vibration coming from the propeller rather than from the engine itself....
So I guess the rattle to public about Titanic felt, was this from the propellor resulting shake, and not the engine itself...
Samuel Halpern
Member
I'm looking to verify some detailed information on the reciprocating engines used on the Titanic. I know that on the battleship Texas (built in the same era) they also had 4-cylindar triple-expansion engines similar in many respects to those on the Titanic. On that ship the engines had a total designed horsepower of 14,000 each at 125 revolutions per minute, with steam supplied at 265 pounds per square inch. Titanic also had 4-cylinder triple-expansion engines with 16,000 HP each at 76 revolutions per minute, with steam supplied at 215 pounds per square inch. On the Texas the cylinder bores were: HP 39 inches; IP 63 inches; and two LP of 83 inches, all with a 48-inch stroke. On Titanic they were: HP 54 inches; IP 84 inches; and two LP of 97 inches, all with 75 inch stroke. Cylinder sequence on Titanic and Texas were arranged the same: Forward LP, then HP, then IP, then LP Aft. The Texas used piston valves on all cylinders, one for the HP cylinder, and two for each of the others. The Titanic used one piston valve on the HP and two on the IP, but used 2 slide valves for each LP cylinders. (Why?)
The crank angles on the Texas were 90 degrees, and the working sequence was: HP, IP, Forward LP, then Aft LP. I don't know what these were on the Titanic. Does anyone have this particular information?
The crank angles on the Texas were 90 degrees, and the working sequence was: HP, IP, Forward LP, then Aft LP. I don't know what these were on the Titanic. Does anyone have this particular information?
Scott R. Andrews
Guest
Hi Sam,
As to the question of slide valves being employed on the low pressure cylinders rather than piston valves, this was the common practice where very low receiver pressures were encountered. Slide valves were certainly less expensive than piston valves as they had no piston rings, and the associated retainers, springs, etc., and all machining was performed on flat rather than cylindrical surfaces. It is however interesting to note that with the Britannic, H&W switched to all piston valves in her engines, which were intended to produce a few thousand more horsepower than those of the two earlier sisters. The pressure at the low pressure receivers was also a few pounds higher. Obviously, there was some advantage to be gained even at the increased cost, for H&W to make this change.
The crank throws on the Titanic's engines were not arranged at 90-degree intervals, something which is quite common in engines balanced on the Yarrow, Schlick and Tweedy system. With this sysytem, no counterweighting of the crankshaft was used. Instead, vibration was reduced or eliminated by carefully balancing the power impulses and turning moments of each cylinder and crank throw, one against the other, with the necessary counter-forces being obtained by adjustment of the relative crank angles and crank sequence, or order of rotation. The the crank sequence and angle of the engines of the Olympic and Titanic, beginning with the high-pressure crank at top dead center, was as follows: (1) H.P.; then, 106° rotation to (2) I.P.; then, 100° rotation to (3) L.P. (forward); then 54° rotation to (4) L.P. (aft); then 100° rotation, returning to H.P. at top dead center.
Best regards,
Scott Andrews
As to the question of slide valves being employed on the low pressure cylinders rather than piston valves, this was the common practice where very low receiver pressures were encountered. Slide valves were certainly less expensive than piston valves as they had no piston rings, and the associated retainers, springs, etc., and all machining was performed on flat rather than cylindrical surfaces. It is however interesting to note that with the Britannic, H&W switched to all piston valves in her engines, which were intended to produce a few thousand more horsepower than those of the two earlier sisters. The pressure at the low pressure receivers was also a few pounds higher. Obviously, there was some advantage to be gained even at the increased cost, for H&W to make this change.
The crank throws on the Titanic's engines were not arranged at 90-degree intervals, something which is quite common in engines balanced on the Yarrow, Schlick and Tweedy system. With this sysytem, no counterweighting of the crankshaft was used. Instead, vibration was reduced or eliminated by carefully balancing the power impulses and turning moments of each cylinder and crank throw, one against the other, with the necessary counter-forces being obtained by adjustment of the relative crank angles and crank sequence, or order of rotation. The the crank sequence and angle of the engines of the Olympic and Titanic, beginning with the high-pressure crank at top dead center, was as follows: (1) H.P.; then, 106° rotation to (2) I.P.; then, 100° rotation to (3) L.P. (forward); then 54° rotation to (4) L.P. (aft); then 100° rotation, returning to H.P. at top dead center.
Best regards,
Scott Andrews
Samuel Halpern
Member
Scott, many thanks for the detailed information on the reciprocating engines. It was just what I was looking for. Is there a reference that describes all this that I can easily get access too? Also interested in the complete feedwater return process, including surface and contact heater details, etc.
Steffen Reichel
Member
Hi Samuel,
there is also another reason for slide valves rather than piston valves!
In steam engines, espacially reciprocating engines we find a force moment, each time the piston reaches top or down end. The pistion weight makes a hard force moment, because it stilll whants to go in example uppwards, but the crank moves over the top death piont, trying to go against the pistons motion mmoment downwards. So, we have at the bearings two forces: One still upwards resulting from the upwarrds force of the piston weigt, the other from the crank downwarrds turn moment.
If an engineer or engine designer does oveerlook this, well, the bearrings will soon be damaged and the engine will start to 'hammer', as result of thee loose bearings.
So, there will a steam rest in the outlet process left, which the pistion needs to commpress, so in our example the piston is slowed down inn its moment, because it has to compress this left steam. So the outlet has a cut--off point somewhat earlier than alll steam has left, and the linkage can be adjusted to more or less cutt-off, resullting in more or less steam to buffer the pistons moment.
But there is a backdraw! Steam can be commpressed, so the space upside our piston will take the left steam and the piston will 'squezze' the steam in alll the available space, so also in the room of the valves.
Another backdraw is, that the leaft stteam is cooler than the new steam comming from the valve inlet to the piston, so the leaft steam needs up some of the heat energy of the new steam, result is a lower steam usage economic in the piston.
Thus: Large spaces will result in the need of larger steam amounts to buffer the moment of the piston, and will in thermical economics be less effective.
Piston valves and small piston surfaces, as in high pressure cylinders found do well with the fine deesigned in/outlet channels of the cylinder and recievers, and many stationarry machines later designed go well with still smaller rooms, because less weight is to buffer, and the higher outlet pressure results in higher compression rathes, so less space and less steam is need for a god economic.
But in Low pressure cylinders wee find a different point: Large pistons have a high fforce moment, and we also need large valves, to deliver the higher amount of low pressure steam, compared to the more little high pressure cylinders. So we need more space the deliver the steam, but less room should be left for the buffer steam and a cut-off with little more steam is need for right buffering.
So the channels and the large diameter of a single piston valve willl resullt in to much room to compress the steam into it, resulting in to little buffering powers. So in stationary engines the piston valve was then divided into two single piston valves, each looking like a large plate nearly directly fitted to the cylinder to give best performances, but hose piston valves need higher maintainance and have a larger and more tricky link arangement....
So in ships the piston valves won't do this job. To large and to high the maintainace and difficult the link arangement. So we need a solution with a single link point, rather than the two need for two single piston valves, and we need a solution with short channels, but high inlet channels diameters. So here the Alan-Trick-Slide Valve is the best choice. It will not a god choice for high temperatures and pressures, because the steam presses the slide to the valve/channel surface, and as higher Temperatures and pressure, as little the oil film below the valve, so in high temperatue and high pressure environment the slide will soon 'scrape' onto the surface and good engine economics will be soon absend. But in ouur ships engine arangeemeent, the Alan--Trick-Valve will do: Low Temperatures, Low pressure and a single linkage point, a low profile and large channeels diameters be little channels rooms make this valve the very best choice.
And Scott: The maintainance of a slide valve is higher than a piston valve, because in pistton valves one had to chance the piston rings, if the valves has a to high leakage, but in slide valves one must level the complete slive valve and channel surface again very precisely to re-seal the slide valve in a point of to high leakage. This common maintainance made, that iin higher pressures and tempperatures the slide valves were not more common and the piston and other valves made it.
So a switch to slide valves rather than piston valves is a decission depending onto pistion diameter, piston moment, amount of buffer steam, death space/room, pressure and temperature, and often in triple expansion engines were the eexhaust steam will be passed to a LP Turbine, pressure and temperature of the steam willl also fit to use pistion valves, if the engine arangement will permit the use.
But a slide valve is no question of cheaper or little maintainace, it is a quite technical decission.
And the strange crank arangement of Titanic. well, it made me guess that there was a little vibration of the reciprocating engines still audible and feelable, because of the different moments of force onto the cranks and shafts...
there is also another reason for slide valves rather than piston valves!
In steam engines, espacially reciprocating engines we find a force moment, each time the piston reaches top or down end. The pistion weight makes a hard force moment, because it stilll whants to go in example uppwards, but the crank moves over the top death piont, trying to go against the pistons motion mmoment downwards. So, we have at the bearings two forces: One still upwards resulting from the upwarrds force of the piston weigt, the other from the crank downwarrds turn moment.
If an engineer or engine designer does oveerlook this, well, the bearrings will soon be damaged and the engine will start to 'hammer', as result of thee loose bearings.
So, there will a steam rest in the outlet process left, which the pistion needs to commpress, so in our example the piston is slowed down inn its moment, because it has to compress this left steam. So the outlet has a cut--off point somewhat earlier than alll steam has left, and the linkage can be adjusted to more or less cutt-off, resullting in more or less steam to buffer the pistons moment.
But there is a backdraw! Steam can be commpressed, so the space upside our piston will take the left steam and the piston will 'squezze' the steam in alll the available space, so also in the room of the valves.
Another backdraw is, that the leaft stteam is cooler than the new steam comming from the valve inlet to the piston, so the leaft steam needs up some of the heat energy of the new steam, result is a lower steam usage economic in the piston.
Thus: Large spaces will result in the need of larger steam amounts to buffer the moment of the piston, and will in thermical economics be less effective.
Piston valves and small piston surfaces, as in high pressure cylinders found do well with the fine deesigned in/outlet channels of the cylinder and recievers, and many stationarry machines later designed go well with still smaller rooms, because less weight is to buffer, and the higher outlet pressure results in higher compression rathes, so less space and less steam is need for a god economic.
But in Low pressure cylinders wee find a different point: Large pistons have a high fforce moment, and we also need large valves, to deliver the higher amount of low pressure steam, compared to the more little high pressure cylinders. So we need more space the deliver the steam, but less room should be left for the buffer steam and a cut-off with little more steam is need for right buffering.
So the channels and the large diameter of a single piston valve willl resullt in to much room to compress the steam into it, resulting in to little buffering powers. So in stationary engines the piston valve was then divided into two single piston valves, each looking like a large plate nearly directly fitted to the cylinder to give best performances, but hose piston valves need higher maintainance and have a larger and more tricky link arangement....
So in ships the piston valves won't do this job. To large and to high the maintainace and difficult the link arangement. So we need a solution with a single link point, rather than the two need for two single piston valves, and we need a solution with short channels, but high inlet channels diameters. So here the Alan-Trick-Slide Valve is the best choice. It will not a god choice for high temperatures and pressures, because the steam presses the slide to the valve/channel surface, and as higher Temperatures and pressure, as little the oil film below the valve, so in high temperatue and high pressure environment the slide will soon 'scrape' onto the surface and good engine economics will be soon absend. But in ouur ships engine arangeemeent, the Alan--Trick-Valve will do: Low Temperatures, Low pressure and a single linkage point, a low profile and large channeels diameters be little channels rooms make this valve the very best choice.
And Scott: The maintainance of a slide valve is higher than a piston valve, because in pistton valves one had to chance the piston rings, if the valves has a to high leakage, but in slide valves one must level the complete slive valve and channel surface again very precisely to re-seal the slide valve in a point of to high leakage. This common maintainance made, that iin higher pressures and tempperatures the slide valves were not more common and the piston and other valves made it.
So a switch to slide valves rather than piston valves is a decission depending onto pistion diameter, piston moment, amount of buffer steam, death space/room, pressure and temperature, and often in triple expansion engines were the eexhaust steam will be passed to a LP Turbine, pressure and temperature of the steam willl also fit to use pistion valves, if the engine arangement will permit the use.
But a slide valve is no question of cheaper or little maintainace, it is a quite technical decission.
And the strange crank arangement of Titanic. well, it made me guess that there was a little vibration of the reciprocating engines still audible and feelable, because of the different moments of force onto the cranks and shafts...
Scott R. Andrews
Guest
Sam,
Regarding the feed cycle, here's a link to a thread where this subject was discussed in some detail: https://www.encyclopedia-titanica.org/discus/messages/5919/43563.html .
The information on the rotational cycle of the engines comes from a copy of the H&W drawing office notebook for the Olympic. There were other such notebooks written as well, there content being slanted towards a particular area of concern, but the drawing office copy was the only one to date that H&W was offering copies of. This particular book, along the existing construction drawings and photographic archive are now at the Ulster Folk and Transport Museum. I don't know when or if they intend to offer copies of any of this information.
As for a reference that you can gain access to that details all of this, at this point in time there is no one single source. You need to have copies of articles from "Engineering", "The Engineer" and "The Shipbuilder", and not just the "specials" that were done; the relevant material was spread out over several volumes. When looking through these volumes, also be on the look-out for articles about other ships of the period, particularly those built by the same builder. While these articles may not contain the exact figures you are looking for, they often can fill in one of two bits of data missing about the builder's practices and fabrication methods, or the particular design principles embraced by the builder.
Perhaps the most important source of information can be found in reading period texts on marine engineering. I've been able to put together a nice little library on the theoretical and practical aspects of marine engineering and naval architecture as it was practiced in the late 19th and early 20th centuries, and this has proven to be a great resource. While you will only find a few specific references to the engines of the Olympic-class (after all, with the exception of the LP turbine, the machinery was of very conventional design, notable mainly for its massive size) you will learn a tremendous amount about the process of designing, building and operating this machinery during this period. The knowledge you gain will help you to interpret what you see in the available photos and drawings for these ships, and will also fill in the blanks when reading the descriptions published in the contemporary trade journals. All of this is most helpful when dealing with arcane subject matter of this sort.
Regards,
Scott Andrews
Regarding the feed cycle, here's a link to a thread where this subject was discussed in some detail: https://www.encyclopedia-titanica.org/discus/messages/5919/43563.html .
The information on the rotational cycle of the engines comes from a copy of the H&W drawing office notebook for the Olympic. There were other such notebooks written as well, there content being slanted towards a particular area of concern, but the drawing office copy was the only one to date that H&W was offering copies of. This particular book, along the existing construction drawings and photographic archive are now at the Ulster Folk and Transport Museum. I don't know when or if they intend to offer copies of any of this information.
As for a reference that you can gain access to that details all of this, at this point in time there is no one single source. You need to have copies of articles from "Engineering", "The Engineer" and "The Shipbuilder", and not just the "specials" that were done; the relevant material was spread out over several volumes. When looking through these volumes, also be on the look-out for articles about other ships of the period, particularly those built by the same builder. While these articles may not contain the exact figures you are looking for, they often can fill in one of two bits of data missing about the builder's practices and fabrication methods, or the particular design principles embraced by the builder.
Perhaps the most important source of information can be found in reading period texts on marine engineering. I've been able to put together a nice little library on the theoretical and practical aspects of marine engineering and naval architecture as it was practiced in the late 19th and early 20th centuries, and this has proven to be a great resource. While you will only find a few specific references to the engines of the Olympic-class (after all, with the exception of the LP turbine, the machinery was of very conventional design, notable mainly for its massive size) you will learn a tremendous amount about the process of designing, building and operating this machinery during this period. The knowledge you gain will help you to interpret what you see in the available photos and drawings for these ships, and will also fill in the blanks when reading the descriptions published in the contemporary trade journals. All of this is most helpful when dealing with arcane subject matter of this sort.
Regards,
Scott Andrews
Andrew Fanner
Member
I've read this board for a while, but never really felt any qualification to post, just fascinated by the wealth of knowledge.. However, as someone who has had a bit of experience in helping running and restoring large steam engines I thought I'd put a word or so on slide valves.
On vertical plant the slide valve is often arrange to fall off the port face, by gravity, when steam is shut off. This can prevent scoring of the port face due to lubrication failure as the lubricating oil is often fed by cups and trims to the steamchest and cylinder, being washed about by steam, or supposedly so
The same is often noticed on C19th steam locomotives with inside cylinders (a very British thing!) the valves may be vertically mounted with still working in a horizontal plane.
Slide valves, within reason, wear in rather than out provided that lubricant is adequate. Piston valves are better for steam tightness as they do not use steam pressure to effect a seal. However, they do require substantially better lubrication arrangements with atomised steam from a forced lubrication system by eg mechanical pumping.
Somewhere in the water feed system will be oil and grease separators. A simple filter won't work, filters will be for undesirable items such as boiler scale and, its been found before, bits of internal casting flash, core sand and other muck. The separators are needed because oil and grease in the feedwater causes priming, water is washed through with the steam and can seriously damage cylinders, either by being incompressible and cracking the castings, or by washing out oil and scoring the cylinder bores.
Anyone based in the UK wanting a feel for large steam plant would do well to visit a museum such as Kew Bridge. The museum has an example of a vertical triple expansion engine. Nowhere near as large as those on Titanic but still large enough to give an impression.
http://www.kbsm.org/engines/triple.stm
The cylinder work platform is about 15 feet or so above the base level.
No doubt the above is in the archives somewhere but I've not go the hang of searching them.
On vertical plant the slide valve is often arrange to fall off the port face, by gravity, when steam is shut off. This can prevent scoring of the port face due to lubrication failure as the lubricating oil is often fed by cups and trims to the steamchest and cylinder, being washed about by steam, or supposedly so
The same is often noticed on C19th steam locomotives with inside cylinders (a very British thing!) the valves may be vertically mounted with still working in a horizontal plane. Slide valves, within reason, wear in rather than out provided that lubricant is adequate. Piston valves are better for steam tightness as they do not use steam pressure to effect a seal. However, they do require substantially better lubrication arrangements with atomised steam from a forced lubrication system by eg mechanical pumping.
Somewhere in the water feed system will be oil and grease separators. A simple filter won't work, filters will be for undesirable items such as boiler scale and, its been found before, bits of internal casting flash, core sand and other muck. The separators are needed because oil and grease in the feedwater causes priming, water is washed through with the steam and can seriously damage cylinders, either by being incompressible and cracking the castings, or by washing out oil and scoring the cylinder bores.
Anyone based in the UK wanting a feel for large steam plant would do well to visit a museum such as Kew Bridge. The museum has an example of a vertical triple expansion engine. Nowhere near as large as those on Titanic but still large enough to give an impression.
http://www.kbsm.org/engines/triple.stm
The cylinder work platform is about 15 feet or so above the base level.
No doubt the above is in the archives somewhere but I've not go the hang of searching them.
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