Steffen Reichel
Member
Dear Samuel,
there is no need in Reciprocating engines to 'run in'... All the bearings have to fit from the first moment.
Most gasoline and diesel engies have to 'rrun in', because here the piston seal rings will 'rub' at the cylinder stoke box, and thus getting warm, and will due heat and adhesion 'polish together' for best sealing.
In steam engines this is not necessary. The pistons have 3 up to 8 spring loaded seal rings, forming a labyrinth seal, so they have no need to seal 100 % pressure, thus need to to polsih to sttrokebox surface in a 'run in Procedure'...
Also the crank bearings and gear bearings were fitted, and these bearrings have to fit from the moment they were mounted. If there is just little dirt, space ot to hard fit, the engine will destruct the bearing. First it will get warm (all bearings will get more than good hand warm, but should not got hot!), then hot. The bearing box is filled with a special alloy, I do not know the technical term for this, but if the bearing gets to hot, because it fitts to hard, the alloy will get liquid again, flow out from the bearing box, leaving the crankpin or sharft running on copper allay emergency bearings, and the engine will start to 'hammer' (a hard knocking sound, called 'hammering' which is the engineers slang for a bad bearing) hardly, and need to be stopped, before the crankpin or shaft get damaged.
So running Titanics engines will start at normal reevolutions, and the high skilled engineers will have a ear to engine sound, because one can hear bearings before they 'flow off'.. Also the would tough the bearings in regular shedules, to feel if the bearing gets to warm, showing a not fit mount.
Consider: A engeneer need to hold his arrm into the revolvering crankshaft to touch the crankpin bearing, any false movement, failure in concentration and the arm is squezzed off by the rude force of crank and drive rod! Same with the excenters which propel the Stephenson linkage, and after this a touuch of the crosshead is also done, just to feel if the croshead fit well to the slide bars, is not hammering and not attached to tight, also feeling if crossheadd attachment of the drive rod is going not to hard and feel if this bearing is mounted well, and not to strong in bearing...
Maybe in Titanics case the Greasers have made this control shedule, and often I know engineers also tough the oil drippping from the bearings and feel if to warm, as first sign of a hard going bearing...
But if there arre no signs of damage or hard going bearrings, well, lets opeen the throttle to all-possibble, and drive the linkage to the nailtippoint, and see what the engine can do... Now all seals have to show if tight and mounted well.... and the engine can show if designed good, because know all imbalances start up to show, in rattle and vibrations... But if that all runs correctly, such larrge engines will run with a deeply hissing noise, like large, giant dragons asleep, were one only can guess about the rude forces pulling to pistons, rods and cranks... such noises can make an entousiast like me shiver...
there is no need in Reciprocating engines to 'run in'... All the bearings have to fit from the first moment.
Most gasoline and diesel engies have to 'rrun in', because here the piston seal rings will 'rub' at the cylinder stoke box, and thus getting warm, and will due heat and adhesion 'polish together' for best sealing.
In steam engines this is not necessary. The pistons have 3 up to 8 spring loaded seal rings, forming a labyrinth seal, so they have no need to seal 100 % pressure, thus need to to polsih to sttrokebox surface in a 'run in Procedure'...
Also the crank bearings and gear bearings were fitted, and these bearrings have to fit from the moment they were mounted. If there is just little dirt, space ot to hard fit, the engine will destruct the bearing. First it will get warm (all bearings will get more than good hand warm, but should not got hot!), then hot. The bearing box is filled with a special alloy, I do not know the technical term for this, but if the bearing gets to hot, because it fitts to hard, the alloy will get liquid again, flow out from the bearing box, leaving the crankpin or sharft running on copper allay emergency bearings, and the engine will start to 'hammer' (a hard knocking sound, called 'hammering' which is the engineers slang for a bad bearing) hardly, and need to be stopped, before the crankpin or shaft get damaged.
So running Titanics engines will start at normal reevolutions, and the high skilled engineers will have a ear to engine sound, because one can hear bearings before they 'flow off'.. Also the would tough the bearings in regular shedules, to feel if the bearing gets to warm, showing a not fit mount.
Consider: A engeneer need to hold his arrm into the revolvering crankshaft to touch the crankpin bearing, any false movement, failure in concentration and the arm is squezzed off by the rude force of crank and drive rod! Same with the excenters which propel the Stephenson linkage, and after this a touuch of the crosshead is also done, just to feel if the croshead fit well to the slide bars, is not hammering and not attached to tight, also feeling if crossheadd attachment of the drive rod is going not to hard and feel if this bearing is mounted well, and not to strong in bearing...
Maybe in Titanics case the Greasers have made this control shedule, and often I know engineers also tough the oil drippping from the bearings and feel if to warm, as first sign of a hard going bearing...
But if there arre no signs of damage or hard going bearrings, well, lets opeen the throttle to all-possibble, and drive the linkage to the nailtippoint, and see what the engine can do... Now all seals have to show if tight and mounted well.... and the engine can show if designed good, because know all imbalances start up to show, in rattle and vibrations... But if that all runs correctly, such larrge engines will run with a deeply hissing noise, like large, giant dragons asleep, were one only can guess about the rude forces pulling to pistons, rods and cranks... such noises can make an entousiast like me shiver...
