By Wayne Grenning
BRIEF HISTORY OF THE OTTO LANGEN ENGINE
Originally written by Wayne Grenning.
Published in February 1991 Gas Engine Magazine
Edited and revised by Wayne Grenning 12/1/ 97 & 1/28/2005 & 3/9/2007
Probably the most historically significant engine ever produced was the Otto-Langen atmosphere engine. Designed through the early 1860’s and produced by Nicolaus Otto and Eugene Langen between 1867 and 1878 it was an important stepping stone for the introduction of the 4 stroke cycle engine later successfully produced by Otto in 1876. Introduces in 1867, the earliest Otto-Langen’s incorporated a very detailed pattern in its main cylinder castings closely resembling that of a Grecian column. (See Fig 1 &2)
From compiled information, these early Otto-Langen engines appeared to vary somewhat with almost each example. The first couple out of the factory used a precarious pair of vertical rods to guide the piston/rack assembly with the main shaft gear. Acting as a crosshead or guide it can be assumed that this system was very prone to maladjustment by jarring of these rods. The most famous and documented of the Otto-Langen examples incorporated this design; it was exhibited in the Paris Exposition of 1867 and was almost overshadowed by the Lenoir noncompression engine. Fortunately for the German duo, engines were judged by efficiency and performance. After several long tests, the grand prize was awarded to them. For its day it was three times more efficient than any gas engine yet produced. None used less fuel per HP per hour, a consequence of the free piston, allowing unrestricted expansion of the gasses. The unique characteristic of complete expansion & free piston in the Otto Langen cycle allowed for more power from the same amount of fuel and as a side benefit cooler operation. Putting aside the machines negative characteristics such as its spastic operation, pounding of the structure in its vicinity, and its loud the rack and piston assembly its success was matched by none. Of the many configurations produced, some incorporated two slide valves, with the second valve controlling incoming gas to the main slide valve. With exception of the very first few made all were manufactured without vertical "cross head" rods and incorporated a simple notched guide contacting the smooth side of the rack to maintain gear contact. Some had individual bearing pedestals some with common bearing rails, etc. All of the earliest designed units were built without governors. These early ungoverned engines incorporated the Grecian column fluted cylinder assembly. Although very appealing to the eye this design was quickly abandoned for a less complicated more cost effective design. This newer more competitively priced 2nd design was in production for almost 5 years encompassing the years of 1868 to 1873. (See fig 3) As with its predecessor, it utilized two shafts. The main shaft keyed to the flywheel geared to an auxiliary shaft supplying power to a pair of intermittently cycling eccentrics. These eccentrics cycled for one revolution when the piston returned to the bottom of the cylinder bringing in a fresh charge of air and fuel in addition to controlling the timing of the flame ignition. One significant mechanical change with the 2nd version was the incorporation of a flyball governor. As engine speed increased, the governor would slowly close a spool valve, restricting the exhaust gas from the cylinder. This restriction increased the amount of time required for each cycle to occur, thus slowing down the engine. As can be imagined operation on the earlier ungoverned 1867 design must have been erratic at best.
In 1873 Two engineers by the name of Wilhem Maybach and Gottlieb Daimler joined the Otto Langen family. They two were brought aboard to help improve the reliability of the engine and further reduce the manufacturing costs. By mid 1873, they were successful in their mission and the third and final version of this engine was produced. (See fig 4). A shorter, simpler and squatter machine was the result. Governing of this engine was also controlled by a gear driven fly ball governor, however in this version, speed control was accomplished by interrupting the pawl from re-engaging the cam. The eccentrics on the auxiliary shaft could only cycle when the pawl was released. This version is, in fact, the first internal combustion hit & miss engine. Many parts, such as the cam and followers, pawl and ratchet were relocated to the single main shaft. A little less than 2000 of these in five sizes ranging from ¼ to 3 HP were produced. Otto and Langen ceased production of these engines in 1878, only two years after the introduction of their 4 cycle silent engine.
Although wonderfully successful, no renditions of the Otto Langens could be considered graceful. With a piston and rack assembly well in excess of 100 lbs. for the “small” 1/2 HP unit, the descending piston hammering or pile driving against the cylinder bottom raised havoc with buildings and foundations (a major disadvantage of the vertical free piston concept). Taking this into consideration, as well as the weight and height, it is not surprising production engines never exceeded 3 HP. Technical books from the late 1800's make mention of the need for a good solid foundation under the engine. Second floor installations usually were inadequate. A 3 HP engine weighed in at a whopping 4,500 lbs. and stood an impressive 12 1/2 feet tall! A pet cock located at the engines exhaust could be used to reduce the hammering of its piston. Greater restrictions of this valve (on the early non governed units) slowed the piston's descent as well as reducing the speed.
Success of these engines were noted by many manufacturers. Crossley of the UK was one of a few that managed to get its foot in the door. Patent rights were granted to this English company in 1869 with production following shortly after. Initial examples from Crossley (their first attempt in engine construction), incorporated the use of a governor serving dual function. Exhaust gas control by a spool valve and interruption of the pawl engagement on the eccentric shaft were both governor controlled. With a close mechanical and operational resemblance to the German engines, the Crossley built units had a smooth sided column without the added expense of casting a Greek column. Vertical Cross head rods were never used (Fig #5). Crossley, famous for its high quality products, entered the engine market by making several improvements and design changes over a span of several years resulting in many variations of the original concept. Even greater than the Otto-Langen deviation between existing examples, Crossley appeared to have spent extensive research on improving the pawl, slide valve and governing operation. During the approximate 11 years of atmospheric engine production, Crossley built almost half as many engines as Otto-Langen. Total production of these engines by all manufacturers is estimated to be less than 5000.
Today, it is believed that only four examples of the original Grecian column Otto-Langen version survive worldwide, with only a couple in operating condition. Rough and Tumble at Kinzers, PA has the oldest Otto-Langen engine in North America, and perhaps the oldest internal combustion engine of any kind in the United States. Being an extraordinary example, it is comforting to know that each August at their annual show it is displayed in its full running glory (see fig. #6). This engine was restored many years ago and is now operated by John Rex at their annual shows. Its unorthodox operation, dual slide valve arrangement, and flame ignition attract crowds of people all day long.
It is most unusual to view engines of such importance today. The fact that 5000 Otto-Langen engines were manufactured in all versions, 130 years ago, and in Europe, contribute to its rarity. Henry Ford Museum at Dearborn, Michigan has a Crossley-built engine of the 3 HP size. Although a static exhibit, its monstrous size, improved design and originality make it a most worthwhile exhibit (see fig #7). The Smithsonian Institution in Washington, D.C. has a mid-model Otto-Langen (fig #8) currently in non-operational condition. Several other examples appear in museums throughout Europe, where it is understood some are run on a regular basis. The list below represents to best of the authors knowledge all remaining Otto-Langen engines world wide.
Known Existing Otto Langen Engines
( not current ! - Page back to see listing of known Otto Langen engines by Manufacturer as of March 2009)
Crossley – Total Production est. 1400 units from 1869 to early 1877
Serial #1 ½ HP made 1869 London Science Museum
Serial # ?? Birmingham, England. Earliest English design
Serial # 379 ½ HP Dept of Mechanical Engineers University of Nottigham
(possibly Deutz as it has many metric fasteners)
Serial # 487 ½ HP Royal Scottish Museum
Serial #641 Henry Ford Museum 1870
Serial #1224 1 HP North West Museum of Science and Technology Manchester
Serial # ?? The Powerhouse Museum Sidney Australia
Deutz Factory in Germany – 2700 units between 1866 – 1877
SN 1 KHD Museum in Germany ½ HP (operable)
SN - The Power House Museum in Australia (second oldest example)
SN - Rough and Tumble Engine association Kinzers. PA (operable)
7 Deutsche Museum Munich (operable)
361 Technische Hochschule Aachen
498 Landesmuseum fur Volk and Wirtschaft Dusseldorf
(Relocated to the Duesseldorf Town Hall about 1990 sold in public Auction Nov 30th 2002) Currently in England - Believed to be operational
SN - 2nd Generation German design. Smithsonian Institution
742 KHD Museum in Germany (operable)
1225 Fachhochschule Esslingen (Esslingen College)
2165 Gesamthochschule Wuppertal (Comprehensive University, Wuppertal)
SN - 3 HP 3rd Generation German design Smithsonian Institution
SN - Birthplace of NA Otto at Holzhausen Mounted on top of tall Granite monument
SN - 3rd Generation in The Dresden Museum, Prague
Langen & Wolf – unknown number of units produced
SN - similar to 3rd generation, on display at the Dresden Museum, Prague
An attempt was made here to give a brief overview of a great milestone leading to the development of the 4 stroke-cycle engine used almost exclusively today. The above abbreviated history was gathered through a multitude of period literature, and hands on documentation of original examples. I would like to thank the following for their assistance: Rough and Tumble Engine Association at Kinzers; Woody Sins, New Hartford, New York; John D. Rex, Chelmsford, Massachusetts; William E. Worthington, Jr., Smithsonian Institution; John Bowdich, Henry Ford Museum.
Fig. 1. Copy of Brochure that was handed out at the Paris Exposition of 1867. This style utilizing vertical cross head rods and secondary safety slide valve. Notice drawing shows the use of cast spoked gears. It is interesting that only solid gears were used in production engines.
Fig #2 : Shown, a copy of the German Patent for the Otto-Langen Engine. (Only one existing with the exact configuration shown Serial #1 in Germany). Within the authors archives are fascinating drawing showing some very curious mechanical linkages and the use of a “spark plug” that preceded the overrunning clutch and slide valve and flame ignition design of 1867..
Fig. 3: Second generation Otto-Langen in magnificent condition (Serial # 498 Approx 1870) showing simpler column construction, incorporation of a governor and redesigned slide valve assembly.
Fig 4: Illustration showing the third and final version of the Otto-Langen engine. Note this new cost conscious design incorporates the use of a single shaft.
Fig. 5: 1/2 HP 1869 Crossley, built Otto-Langen at a museum in Birmingham, England Note very similar design and construction to the German version shown in Fig 3. Photo: John Rex.
Fig. 6: 1867 1/2 HP Otto-Langen at Rough and Tumble Engineers Historical Association of Kinzers, PA. One of the earliest IC engines in our hemisphere. Serial number believed to be under 10. Photo: Author
Fig. 7: 3 HP (Serial #641) English built Crossley Bros. Otto-Langen, showing improved design, incorporating double flywheels, simplified construction. Author standing alongside to demonstrate the massiveness of this machine. Located in the collection of the Henry Ford Museum. (Author photo)
Fig. 8. Otto Langen at the Smithsonian Institution in Washington DC