On this page we investigated how, in the early 1800s, the bearings of steam engines (and other machinery) were lubricated. Tribology, then, was still very much in its infancy. On the present page, we'll move forward some 50-60 years. How were things then, lubrication-wise?
The short answer .... worse!
In fact, tallow and rape oil were still the (only and universal) answer to the engineer's need for efficient lubrication. Real progress started only with the discovery and exploitation of those vast deposits of mineral oils at the end of the 19th and beginning of the 20th century. Take for instance, Grothe's famous "Mechanical Technology" of 1866. The descriptions under the chapter "Oil" are nearly identical to those of Rees, fifty years earlier ....
The same, however, cannot be said of steam engine design. In the 1820s, a quick evolution set in and by the 1850s, the design of beam engines had much improved. They then were provided with cast iron beams and frames. They ran at somewhat higher speeds, say 25-35 r.p.m., depending on size. Direct-acting stationary engines by now were available in several types: vertical (flywheel at top); inverted vertical (cylinder at top) and horizontal. Speeds varied with the type, say up to 45 r.p.m. for vertical; 55 r.p.m. for inverted vertical; and 35 r.p.m. for horizontal engines. In marine practice, there was a wide gap between the behemoths powering gigantic paddlewheels (at less than 10 r.p.m.) and the compact and fast-running inverted vertical screw engines (up to 60 r.p.m.). In locomotive practice, running speeds were still quite low, due to difficult design conditions and maintenance problems; hence the extremely large "drivers" (driving wheels) with diameters of over 2 metres!
So, all-in-all, speeds of 50-60 r.p.m. were not uncommon. These required oil lubricaton. Tallow won't work at such (relatively) high speeds. Rape oil; there wasn't anything else. But it was not really satisfactory. We'll have a look at two text-books for (aspiring) engineers, dating from the 1860s and 1870s, to sketch the state-of-the-art (and its problems).
The first book, Bourne, J.; A Catechism of the Steam Engine; Longman, Green, Longman and Roberts, London; 1861, covers the ground in Questions and Answers.
Have you any information to offer relative to the lubrication of engine bearings?
A very useful species of oil cup is now employed in a number of steam vessels, which, it is said, accomplishes a considerable saving of oil, at the same time that it more effectually lubricates the bearings. A ratchet wheel is fixed upon a little shaft which passes through the side of the oil cup, and is put into slow revolution by a pendulum attached to its outside. In revolving it lifts up little buckets of oil and empties them down a funnel upon the centre of the bearing.
Instead of buckets, a few short pieces of wire are sometimes hung on the internal revolving wheel, the drops of oil which adhere on rising from the liquid being deposited upon a high part set upon the funnel, and which, in their revolution, the hanging wires touch. By this plan, however, the oil is not so well supplied at slow speeds, as the drops fall before the wires are in the proper position for feeding the journal.
Another lubricator consists of a cock or plug inserted in the neck of the oil cup, and set in revolution by a pendulum and ratchet wheel, or any other means. There is a small cavity in one side of the plug which is filled with oil when that side is uppermost, and delivers the oil through the bottom pipe when it comes opposite to it.
Bad fitting, deficient surface, and too tight screwing down. Sometimes the oil hole will choke, or the syphon wick for conducting the oil from the oil cup into the central pipe leading into the bearing will become clogged with mucilage from the oil.
In some cases bearings heat from the existence of a cruciform groove on the top brass for the distribution of the oil, the effect of which is merely to leave the top of the bearings dry. In the case of fully revolving journals the plan of cutting a cruciform channel for the distribution of the oil does not do much damage. In other cases, as in beam journals, with short stroke reciprocal motion, it is most injurious. The right way is to make a single horizontal (longitudinal) groove along the brass where it meets the upper surface of the bearing, so that the oil may be all deposited on the highest point of the journal. This channel should, of course, stop short a small distance from each end of the brass, otherwise the oil would run out at the ends.
The first thing is to relax the screws, slow or stop the engine, and cool the bearing with water, and if it is very hot, then hot water may be first employed to cool it and then cold. Oil with suphur intermingled is then to be administered and as the parts cool down, the screws may be again cautiously tightened, so as to take any jump off the engine caused by the bearing being too slack.
The bearings of direct acting screw engines require constant watching, as, if there be any disposition to heat manifested by them, they will probably heat with great rapidity, from the high velocity at which the engines work. Consequently, every bearing of a direct acting screw engine should have a cock of water laid on to it, which may be immediately opened wide should heating occur. It is advisable to work the engine constantly, partly with water, and partly with oil, supplied to the bearings. The water and oil are mixed by the friction into a species of soap, which both cools and lubricates, and less oil moreover is consumed than if water were not employed. It is proper to turn off the water some time before the engine is stopped, so as to prevent the rusting of the bearings.
We now turn to A catechism of High-pressure or Non-condensing Steam Engines; Roper, S.; Claxton, Remsen & Haffelfinger, Philadelphia; 1873. This book offers an extensive Set of Rules for the care and management of the steam engine.
(third rule) - The oil or tallow should never be admitted to the cylinder until some time after the engine is started and the drip-cocks in the cylinder closed, as the tallow would otherwise be carried out by the condensed water and lost.
(tenth rule) - All the parts of the governor should be kept perfectly clean and free from the gum formed by the use of inferior qualities of lubricating oils.
(eleventh rule) - No more oil should be used on an engine than is absolutely necessary, as it is not only a loss, but often detracts from the appearance of an engine and greatly interferes with its free and easy movement, from the accumulation of gum and dirt on its working parts.
(twelfth rule) - In case the crank-pin should heat -- which is a common occurrence with engines having a narrow bearing on the pin, but more particularly with engines that are slightly out of line -- remove the key and slacken the strap and box of the big end bearing; then pour in some flour of sulphur with a liberal supply of oil; then adjust the key, and the trouble will generally disappear.
(thirteenth rule) - If the pillow-blocks of an engine should heat badly, remove the caps and pour in a good supply of pulverized bath-brick and water while the engine is in motion; after doing this for some time, wash out with oil and wipe the bearing clean with cotton waste, and it will be found to give permanent relief.
(fourteenth rule) - In case any of the bearings of an engine should heat through the accumulation of matter deposited from the oil used; or sand, grit or whitewash as used in polishing steel engine parts, being dropped into the bearings: use a strong solution of concentrated lye with oil when the engine is in motion.