Lubrication and related matters from Steve Sattler

[daveklepper]

Lubrication for the Wheel.            A history.

(for ... The World of trains!)

With the invention of the wheel at about 3800 BCE; the early Bronze Age, in the Mesopotamian valley; one problem became instantly relevant.

How to allow the wheel to slide on the axle with the minimum amount of friction and wear?  Soon the Sumerian peoples of Mesopotamia and then the Egyptians were covering the axle with leather to reduce the friction and wear.

Later on, as tools became more sophisticated   they cut the wood of the wheel ‘better’ to allow a more comfortable fit against the axle. All wheels were made of wood slats glued together with a paste of dried, rotting cow intestines.

Prepared metals were still rare.

In the 18th Dynasty in Egypt [the period of Joseph], they had expert cart-builders who would use a harder wood for the axle and a softer wood for the wheel. The softer wood would “wear-in” fast and thus reduce the friction.

Soon , animal fats, especially the quality fat around the kidneys was used to smear the axle contact with the moving wheel. These are the first Greases.

             Grease today is a specialist product –either natural oils or synthetics. There are over 3000 specialist greases on the market.

During Roman times, teams of slaves were trained, and given precedence as “specialist” slaves to prepare the fats, oil the wheels and keep the family or military chariots in ‘running’ condition.

We now jump to 1854; Birmingham: The Industural Revolution,   that forced the ‘inventors’ to create the new Science of Tri-bology.—[def: reducing friction between contact metals.]. 

             (A more scientific definition: the effects and techniques to reduce or increase the friction between relatively moving surfaces.)

Actually Leonard da Vinci [1452-] had already written a thesis on friction and how to reduce it.

1809-1830: Soon specialist lubricants were been manufactured to allow the new trains to travel at ‘speed’. In those early years.

In those days ‘speed’ was about 25 m/hour.

The combination of calcium stearates (soaps) and animal oils became the standard of keeping train wheels turning freely.

Different combinations of soaps, and vegetable oils were constantly produced to cater to the new fast-moving gadgetry: -Trains, cars, planes and engines.

Meanwhile, train-engineers were discovering that the three main moving contacts for any train were,  [1] The wheel and the axle rotating under the base support,  [2] The wheel rolling over the rails, and  [3] the piston, motor or drive shaft from the engine connecting the drive to the wheels.

       Early trains, that were an evolution from the wagon, had free moving wheels on a fixed axle.  This quickly, was replaced by a one-piece unit of two wheels and one axle -as one welded and sealed unit. The wobble of a wheel was the critical factor that changed the concept;  that the wheel needs to be the part fixed to the rotating axle.

The wear, vibration and ‘shock’ of a wobbly wheel on a metal rail, forced the engineers/designers, the passengers and the train-owners to find a better solution.

The immediate problem was the way that the whole axle will rotate [at speed, with minimum friction] against the base of the locomotive or the carriage.

In 1794, a Welsh iron master patented the first modern ball-bearing. Even in Roman times some primitive ball-bearings [from ivory or bronze] were known but with the production of the standard, smooth and very round ‘ball-bearing’ the whole concept of a wheel/axle  rotating against a fixed base or support suddenly became modern!

Soon housings for the ball-bearings, and lighter oils were been used to allow more efficient movement with less friction.

Speed has always been the un-written motto of trains. The first trains of 1804 got 8 k/h as their service, by 1825 it was up to 24 k/h and by 1854 a steam train could do 132k/h. The paragon changed as electricity became the standard. By 1903 an electric train [‘Siemens’ in Berlin] could do 200 k/h. By 1955 it was 331 and then 1990 up to 515. New technology now allows HS trains to do 575 k/h.

[The TVG v150; in France holds the record].

As the Japanese Shinkansen [1959; Sharyo], the French TGV [1969; Bombardier of Canada, Alstrom] trains and other high-speed trains {Italy, USA, UK; and now the Chinese 'Harmony' } became to be developed: concepts changed. The standard on most modern trains is now a pair of wheels fixed to the high-quality steel axle, and then the axle rotates against the supports in the bogie [Bogie in UK English ; Truck in American English]. The rotating axle [and these trains now travel at 360+ m/h ], is separated from the supports by rod -bearings [of steel, or ceramic], or conical -bearings [from 1934 and then again 1965]  , or –more rarely by ball-bearings. A light lubricating fluid, controlled by sensors and an injection system, in a closed box [container] keeps the bearings from heating up, or causing un-necessary friction.

North American train technology is frequently technologically different from European ‘train-science’. A simple example is that the North American “Journal bearings”   [The box or area where a rotating metal wheel or axle meets the support under the ‘truck’] could be made of Brass covered with tin and lead, creating a softer metal touching the harder STEEL of the axle. This theoretically reduces the ‘friction’ between the axle and the support.

Before the introduction of ‘sensor-technology’ near the rotating axle, in many North American trains, the ‘Journal-box’ at the end of the axle would have cotton waste or stringy cotton placed just under the screwed down lid, to allow a reservoir of oil or grease to constantly infuse itself into the space of the moving parts.

The science in this branch of Tribology is constantly improving.

For the O Series of Journal bearings for the 1964+ Shinkansen line trains a new idea of steel bearings made from three sets of rotating bearings in the same small metal Journal -box was introduced. The two main bearings were elongated steel bars -to take the LOAD of the train, and the third bearing was only steel ball-bearings-to take the horizontal forces on the axle as the High Speed Train took a curve. This technology has been improved upon, and even more speed can-be extracted from these Journal bearings now with composite spacers in place.

The olden days: A long period from the 20s till the late 70s had teams of rail-crew greasing, re-greasing and constantly checking the sealed ‘Journal’ boxes against the axles for “friction”, [called a ‘Hot-box’] seizure or wear around the axles. There was a big industry in producing the right grease for each type of engine, carriage or speed of movement. Many greases were color-coded.

The Grease industry knows that GREASE is made up of three major components. The oil, a thickener and certain additives.

The oil will be processed natural [black] petroleum or  rarely an artificial oil -[manufactured chemically in an industrial  laboratory].

The Thickener is essential; it allows the grease to be placed physically on the right place, and kept there as a semi-solid. As the two surfaces begin to move-against each other—then the heat, and turmoil will allow the thickener to become more liquid, and thus functional.

Additives are added to prevent corrosion, rust, electrical sparks and magnetic fields. Many additives today are plastic molecules.

In many Modern trains [especially the Swedish HS systems -The X2000 by ADtranz 1990++] , the axle box is a sealed unit, that never needs maintance. The lubrication fluids are sealed inside, and polymer separators keep the wear between metals to a minimum. These units can travel 1 million kilometers with-out any maintance. The lubrication fluids are specialist combinations.

Historically, in the Modern era, steel ball bearings were the first form of moving separator between the support and the rotating axle. Later on  [in Germany :The 30s], short steel rods replaced the balls, then different shapes and sizes of conical rods were found to be easier to 'keep in place'. Today conical rods are the standard, and many are made of ceramic materials.

         A second problem was the contact of the metal wheel against the rail. The rails are smooth [from manufacture and wear] , and either water, snow or wet leaves [The Autumn problem-in North America], allowed the wheels to slip on the rail. [The famous stories of the J&J Navon train 'slipping' her way up to Jerusalem -100 years ago]  It  was soon discovered that the actual contact of the iron [steel] wheel to the rails was only on 1/8 of the width of the wheel.   Trains starting from The Standing Position, or trains climbing a 5% grade had problems with slippage, wasted energy and the occasional accident [See: The Atomic Train-a movie]. Some trains now automatically spray sand, on the rails, when necessary, if the conditions of the contact deteriorate.

In HS trains, especially taking curves, ecology friendly lubricants and /or sprayed sand are sensor-activated against the flange of the train wheel to reduce friction or noise. The constant problem of how a HS train should take a curve is critical to the "service" that HS trains gives. Tilting trains, slower speeds and different shapes of the rails are used in addition to  sensor activated lubrication against the rails. The TGVs approaching Lyon have this constant problem.

      The last major problem was the wear, strength and co-ordination of the drive shaft from the [diesel] motor to the wheels. In those trains that have electric motors for each drive wheel, the RPM of each motor needs to be coordinated for “all-working -together”. There is no value in having 6 motors for 6 drive wheels and only 4 or 5 actually work together and the other 2-3 either work too fast or too slow.

In the steam trains-the [steam] Piston housing had to be sealed, clean, leak-proof and well oiled.

The modern World of trains now revolves around three types of "Engine".

 [1] Electric trains- collecting their energy from an over-head wire, or [2] Diesel –electric units that the Diesel motor rotates into the electric motor that makes the electricity for the wheel-motors. [3] Diesel units that directly [and mechanically] connect the diesel engine to the wheels-through a gear box.

Nearly all HS trains now have a Pantograph (or two) on the roof to collect energy from the overhead wire(s), and this has been found to be the most efficient and practical system. This is called a  pan in the USA.

Maglev trains –[still a rarity; to Shanghai Airport has one ], use a magnetic cushion to allow the train to FLOAT [FLY] on a computer controlled magnetic field. Only four countries have commercial Maglev trains in use. Japan from 2005: The longest tracks, China from 2004 and St Korea from 2016. Germany from 1971 has had test tracks and trains in use-with some incidents. Birmingham had a 1984 Maglev Airport system at one time. It was closed  down later on. There are 14 other countries that are now designing, building and applying Maglev systems for commercial use. Tel Aviv will have a working Maglev System [The Skytran company- Nasa technology] by 2019.

All Maglev systems have no wheels, no overhead wires and less maintance and lubricants.

      During WW1, The British in Egypt discovered that the Ottoman Empire [with German help] had induced the North African [Arab] Senussi  Sect to raise a jihad against the British and Italians in Libya and Western Egypt.  From November 1915 till February 1917 some 40000 British and allied troops had to fight this enemy.

The distances and the terrain were very problematic. Consequently,  rail-lines  and train services had to be introduced. The terrain was sand, shifting sand, gravel and occasional oases. Several large depressions had to be descended into [by trains], and then ascended in reverse. Water was a problem, and the trains had to carry extra  water tanks.

The British built three 600mm tracks into the Western desert. A short track -in the North -from Khatatba on the West Nile to Wadi Natrun.  [2] A longer line from Sandagfa on the Nile to Blockhouse B6    just at the Eastern edge of a sandy region. [3] A third , longer line , at the South from the Nile at Oasis Junction to Water Dump A;    well into the desert.

The day temperature would hover around 48 degree and at night frost, ice and freezing winds were the norm. Finding shade was a problem.

Sand flow, sand winds and shifting sand walls [or mountains] constantly damaged or covered the rails.

The steam trains of this era had to cope with these extreme conditions. The tracks laid were 600 mm [from stocks  in Egypt].  The trains were borrowed Egyptian engines and various carriages. Coal was brought by ship from England and local wood was both unusual and unreliable as fuel.

Trains could only travel at low speed, the metal of the trains became extremely hot and on many open carriages canvas, wooden or thatched covers [a roof] had to be erected to protect the men.

Over-night many rails became covered with sand, and crews had to walk before the train to clear the tracks. Track supports would sag, and maintance crews had the impossible tasks of propping-up an unsupported section.

The only minor advantage was that the Senussi warriors [Bedouin] didn't try to damage or block the tracks.

Maintance was critical and difficult. Along the tracks concrete block houses had been built—to store water, for security, allow staff to sleep/live nearby and to act as places to unload equipment in a desert with very few geographic objects.

Military supply Camel caravans or troops of lightly armored cars (many were Model T Fords), would meet the train at the Block-house and collect supplies or men.

The lubrication of moving parts on these Steam trains -in the sandy desert was critical. Sand has the ‘magical’ ability to find any smallest space to sneak into. Egyptian train-maintance crews were constantly lubricating or cleaning away gluey sand from wheels, axles, and the various arms of the pistons.

Junction boxes got special attention. Whenever a junction box was un-screwed by an experienced team, one member of the team kept a canvas sheet, acting as a wall between the open box and the windy [flying] sand.

The British had an extensive Engineering unit of ‘train-engineers’ that did their best to keep the steam-trains and rolling stock in working order. It was difficult work. Already at the start of WW1. the British Military had made an effort to find qualified men to run and maintain the “war-trains”.

Many locomotives had fairly complicated built-in lubrication systems,   in place. It took some degree of experience to know and maintain “displacement lubricators” [steam pushing oil into pipes and pistons], or how to maintain Bogie pivots by “Capillary action” : how to  control the size and usage of the Worsted Yarn that was the medium for oil to get to the right place.  It took a trained engineer or train-driver to know when to stop or reduce the Yarn from dripping onto the rails--when stationary. Oil on rails was a serious problem and a waste of limited oil.

Some engine cabins had small glass windows into the oil reservoir to supervise the amount of oil that was been used to maintain pipes and pistons. A trained engineer had to supervise the amount of this oil-drip into water in the reservoir.

Another WW1 trick was to pour a little garlic oil into the Running gear oil- container, and the smell would tell the maintance-team if the oil was running low.

Senior officers knew that The rolling stock and trains were-in the main-rented from the Egyptian State Railways, and they had to be returned --in usable condition, otherwise some compensation would need to be paid.

 

A special case: 

A side issue is the “don’t oil systems”.    Third-rail equipment: a train or tram that gets the power from a THIRD-RAIL—placed near the metal rails, but protected by a cover and insulators from all contact with the ground, the real rails, the passengers, accidents and the weather---is a continuous metal strip, carrying 1200 or 1500 Volts -DIRECT CURRENT.  The ‘metal Shoe’ of the passing train will pick up the energy to power the train. Hamburg has a 1200 V system, Culoz in France has 1500V and so does the Guangzhou Metro [China].

The Third-rail runs parallel to and next to [frequently on the RIGHT] the two real metal rails but never touches the real metal rails. The distance from the Third-rail to the metal rails is constant.

The London Underground, and the older Milan Metro [line #1] use yet another system:  A FOURTH -rail. This is a ‘live’ metal rail, carrying -210 DC Volts [Minus Volts] , on insulated rubber pads -in the center, between the two real metal rails. This extra rail provides the TRAIN with 630 DC Volts of energy. The Third rail [This time on the Left!], carried 420 DC volts and the Central [4^th rail] , carries -210 Volts.

This is a cumbersome system and fairly dangerous. It solves the ancient problem that Victorian-era metal pipes and metal tunnels could become energized and kill or cause sparks by ‘electrical-leakage from Third or metal rails. [Real metal rails with any over-head electrical input   act as the ‘ground’ for the electricity to close a circuit.]

 Other Fourth-rail systems [The London underground+regular trains, or the Paris Metro use a 750 DC Volts Fourth-rail] also exist.

The fourth-rail is more exposed than the Third-rail and this is a bigger ‘weather’, oil, grease, abuse or ‘destruction’ problem. It had no protective cover.

Maintance crews have the difficult task of ‘never’ touching this Third-rail, turning it off during maintance, and been careful never to spray oil on this metal strip. Any oil, dirt, weather damage or dead animals that ‘cover’ this live Third-rail will interrupt the power supply and cause problems. Obviously this Third-rail will have interruptions in its continuity; at level crossings, between sub-stations and in ‘public’ areas. Train technology knows how to ‘keep-the-train-running’ even when the live metal strip is not there. Oil spray from many outside sources, is a constant problem and needs to be cleaned off.

Third-rail systems are now been ‘designed-out’ of the modern train concepts and the pantograph is the accepted solution to efficient, safe and fast travel.

The technology and engineering of modern trains is now heavily SENSOR inundated. Sensors now tell the computer screen how the train is feeling--just like the Physiology of a Human. Both the driver and some distant regional control-box staff get up-to -date information about the health or “problems” that the train is feeling. The lubrication processes are now almost completely automatic. The right oils/greases are injected into the right places, controlled by sensors, electro-mechanical valves and other sensors keep an electronic eye on how efficiently that moving part is working.

The main micro-damage and wear in an axle and bogie union is when the train is just starting up or stopping. While the train is moving, the rotating axle has a thin film of oil -as a cushion--between the moving parts.; and in fact, the two metals do not touch. If the train is stopped, or just moving then the oil cushion is no longer there, and the metal is -in fact,--scraping against metal. This causes wear, micro-damage and tiny metal flakes now ‘pollute’ the ‘clean’ oil. Either, in the factory -before the sealed container is closed -the oil should be changed after a few tries of ‘testing’; or every few ‘thousand’ kilometers the oil is changed, and the micro-space cleaned-with steam.

As “The Train Civilization” improves more and more    and citizens accept that taking The Train to work,  from city to city or  across a continent -is the right thing to do;  then train technology, lubrication systems and the new “plastically” oils are introduced :   then wear and tear, damage, seizure or inefficient contacts between moving parts will become less of a problem .

The Train, the System and the passenger will get a better service.

Steve Sattler

February 2018

[Electroliner 1935]

Dave, I don't know why you posted this but If I were a professor grading this paper, I would have many issues. But one I want to mention today is that I did not see any mention of the long use of 600 volt third rail use in rapid transit systems in New York, Chicago, Philadelphia, Boston, etc. BART with 1000 V DC and others with 750 Volt third rail. Not sure what voltages are used in Paris and other subways on the continent but most are third rail. And the North Shore line was a very successful 600 V trolley pole operation without pantagraphs. Granted, speeds under 90 mph. Perhaps his studies were limited to european systems?

daveklepper

Historically, in the Modern era, steel ball bearings were the first form of moving separator between the support and the rotating axle.

A second issue is that ball bearings while used in some railroad applications, (diesel and generator bearings) most axle bearings were originally brass and are now tapered roller bearings. 

[daveklepper]

I posted this as received from Steve, and will be glad to pass on all comments to him.  I will wait for some more.   I am aware of the points you are making but currently prefer that the citique come from others, not me.

I had already pointed out that tapered roller-bearings are typical today, but Steve insists on calling them "rods."

Thanks!

The new information for me was the transition from wheel on fixed axle to pair of wheels and and axle as one unit.  Steve and I had some discussion on this point, and he said he saw 1870-era horsecars in an Italian Musem that still had fixed, non-rotating axles.  I responded that possibly the wobble introduced by wear in such an arangement would be less of a disaster with grooved streetcar rail, which was introduced in Europe long before North America, but the very early horsecar at Shore Line Trolley definitely has rotating axles and journal boxes.