|
NOTE: Page is presented partially complete to permit use of finished data and methods. Updates will follow as car classes are developed. There should be enough projected work to keep anyone interested quite busy. Question about methods, measurements or any facet; disagreements, alternate views, comments and problems can be posted at COUPLER HELP GROUP. . In the early days, practices were set by individual railroads or even a local shop foreman. Many varied coupling devices were copied from horse drawn wagons or dreamt up from wild imaginations, without any engineering knowledge. Some devices were simple drawbars, while various chain connections were common. Eventually railroads met and interchanged cars, forcing an agreement of practices between them. A common, inexpensive practice consisted of bolting two large wooden, dead blocks to end sills with a hook between them. A length of chain was strung between them with enough slack to permit negotiation of curves. This often lead to damage or derailments. Sprung buffer discs were common on passenger cars, not unlike those used in Europe in later years, but closer spaced. Later the link and pin was developed to remedy the situation. It consisted of a drawbar with a horizontally slotted head into which a single chain link was inserted. It was held in place by a pin, inserted through top and bottom holes. Heads, links, pins and compatibility varied widely as did height above rail. With vertical offsets, "crooked" links were offered to couple cars with different head center heights. A common link distance between pin centers (LD) in the pulling position was about 8 1/2". But drawbar faces varied greatly with about 2 1/2" distance between face and pin hole center (F-C). In pushing faces touched, while pulling, face distance (FD) would be: FD = LD - 2 * F-C = 8 1/2 - 5 = 3 1/2" The PRR set early freight car, distance from face to end sill (F-ES) at 7". This would yield a end sill to end sill distance of(ES-ES): ES-ES = 2 * F-ES + 3 1/2" = 17 1/2". Later the CB & Q set F-ES = 9" for ES-ES = 21 1/2"; while still later, the NYC set F-ES = 11" for ES-ES = 25 1/2". During the 1870's various hook type heads were developed for passenger cars. Among these were knuckle types, with the Janney emerging as the most successful . Slowly they found their way to freight cars. Some knuckles had slots and holes to accommodate links and pins. Air brakes were introduced about this time. Probably referring to knuckle coupler use, in 1879, the Master Car-Builders Association safety standards recommended a 12" distance between coupler face and end corner on house and other cars with ladders and no end sills. This would yield a 27 1/2" end corner to end corner distance (EC-EC). This value was later applied to ES-ES on most cars and remained as standard until about 1910, when larger knuckles were introduced. A very common practice was the use of sturdy 8 or 10 inch timbers for end sills. Especially with chain couplings, for clearance on curves, many were tapered back toward side ends. Position of body ends varied from complete end sill exposure to almost none, independent of time frame. Cars grew in size as did spacing between them. Many older cars eventually were converted to knuckle couplers, but still retained unnecessary buffer blocks and other features. This included some cars from the 60's. By the 1890's some semblance of order developed. APPROACHING THE PROBLEM Before examining the individual prototype cars, it might be wise to scan the models marketed over the years. Some are available, while others may be found at actions , flea markets. Most plastic models came with Talgo trucks, requiring extra clearance, while craftsman kits and brass usually had mounting pads. These should present only minor problems. IHC "work" cars, MDC and a few others use cast-on boxes, which will require milling out interiors. Only a few cars offered were antebellum (Mantua), and only freight cars survived past the early 70's in revenue service on most roads. For the sake of automatic operation, it would not be totally unbelievable to use knuckle couplers with air hoses throughout this era. Common knuckle couplers had a pulling face to horn distance of about 8 3/4", while the shortest HO coupler, the Kadee 711, measures about 12.2". However, in most cases, the horn can be recessed under end sills easily. The highest projection, over the trip pin, is only a few thousandths above box top. This is virtually unobtrusive, except for the purist. Since the supplied box is required, most applications necessitate the removal of the lip to achieve desired spacing and mounting. The pulling face to box front edge is .102" = 15.9", which exceeds desired clearance distances. Normally padding shims are required, removing any head clearance problems. Floor height may require adjustment before determining pad requirements. MEASURING ROLLING STOCK HEIGHTS can be tricky, but some aids are easily made. Although the suggested pulling position reference can be established; due to design requirements, the operating spring is behind the center post and can be compressed under load. In long trains, this could increase spacing noticeably. It will be maximum at the head end of the train and gradually decrease toward the tail. For this reason, the neutral, no pull, coupler position is used as reference in discussions. Rather than coupler appearance, the most obvious obstacle to realistic representation, throughout this era, is truck wheel base and style. Almost all, offered with models, have 5' 6" wheel bases, while prototype freight cars used from about 3' 4" to a later 5'. Usually much longer, some 4 wheel passenger car trucks exceeded 7'. Although not the wrong style, Mantua's 1860 freight cars have the same wood beam trucks as their passenger cars at 5' 6", while similar cars used closer to 4'. Precision Scale offers most of the usable Kemtron side frames with HOn3 bolsters. But in spite of requests, no standard gauge bolsters have been developed. NOTE: Care must be exercised when determining lengths over couplers from drawings or text, since link & pin were referenced at drawbar faces, while knuckles used pulling face. The type used is often omitted and the difference may be large. FREIGHT CARS Since many early cars were basically flat cars with appended sides, ends, tanks or hopper doors, some of the model cars can be modified very easily to provide a wide variety of rolling stock, even into the 90's. Those that were specifically designed, seemed to follow the same general practices. With very few exceptions, distance tolerances can be very close. In general up to about 1870, most cars appear to be less than 30', with hopper types about 22'. Until the introduction of link and pin couplers, they probably used hook and chain with, too often omitted on models, dead blocks to absorb shock. Pulling distance was set by the length of 3 links, which varied along with the dead block extension, shape and other dimensions. Many drawbar types were tried, but due to incompatibilities were not common. In 1872 one link and pin type was patented and probably due to its compatibility with chain links, this type became common. Although not necessary with these, deadblocks were continued to accommodate older drawhook and chain cars. Car lengths gradually increased to about 36' and spacing settled as discussed below. Striking plates were added to sills to limit head travel. In 1878, Janney reissued his 1872 patent for an improved knuckle coupler. Probably due to cost, initial use was for passenger cars and even though link and pin were considered dangerous in 1888, knuckles were not common. But their superior performance and safety gradually led to the replacement of link and pin during the 90's. Spacing increased with their use and deadblocks disappeared. During the interim, slots and pin holes were provided in the faces for links. With larger heads and many refinements, the basic design is used at present. Note: Because it is assumed that knuckle couplers will be used; for consistency on models, pulling length will referred to as length over pulling faces (LPF), which will include the additional link distance where applicable. For all cases, a reference point (REF) must be established as the optimum for judging spacing. This may be the end sill or end corner dependent on type of car or height. The important reference to mounting center distance (REF-MC) is found by subtracting the prototype pulling face to reference (PF-REF) from PF-MC (model coupler): REF-MC = PF-MC - PF-REF From MEASURING COUPLERS, for the Kadee 711, PF-MC = .360: REF-MC = .360" - PF-REF (prototype) Earlier freight cars, with link & pin, would use the ES-ES = 17 1/2" and PF-ES = 8 3/4" or .100". Thus for end sill reference: REF-MC = .360 - .1002 = .260". Since the 711 pulling face to horn distance = 12.5", the horn must be recessed behind the sill about 3.75". The sill will be approximately at the trip pin center. See 711 EVALUATION. NOTE: From data in examples, this is the practical minimum spacing for sharp 15" or 18" R, requiring the addition of deadblocks to avoid corner collisions.. FLAT CARS Since they are always judged at end sill level, their spacing is easiest to determine. Their study will provide some insight toward solutions in more difficult car types. For the pre-1870 era the only common car groups available are, Mantua Civil War, IHC oldtime work and the rarer Redball/Cannonball Car Shops cars. Both the former have similar dimensions, but require different approaches. As shown in IHC OLDTIME WORK CAR EVALUATION the mounting holes are very close to to the correct REF_MC. However they must be drilled through with a tap drill for screw purchase. The mounting surface must be milled to height of the 711 box. Mantua and others will require shims. In all cases, the endsills will touch during pushing and require wider spacing and deadblocks on sharp curves. Through most of the 70's and 80's, most cars cars used link and pin and the above spacing fits well. BACHMANN and AHM offered cars in this era with easily removed talgo mounts. These surely survived into the 90s and were converted to knuckles and many trains had LINK AND PIN MIXED WITH KNUCKLES consists. Probably using knuckle couplers, a later flat had a length over pulling faces (LPF) of 35' 3 1/2" and a length over end sills (LES) of 30' 0". The difference reveals the spacing between end sills (ES-ES): ES-ES = LPF - LES = 2' 3 1/2" or 27 1/2". Half this is the pulling face to end sill distance (PF-ES): ES-ES = PF-ES / 2 = 13 3/4" = .158" The 711 PF to box edge = 15.85", so edge will be recessed behind end sill. The end sill (REF) to mounting center distance (REF-MC) may be found from: REF-MC = .360 - PF-REF = .360 - .158 = .202 " A slightly later version had an LPF of 38' 8 1/2" and LES of 36' 5" for an ES-ES of 28 1/2" and PF-ES of 14 1/4". The REF-MC would be .194". Since the larger 12" heads were introduced about 1910, earlier cars would use the above spacings. Since many models were provided with clearance for talgo mounts, only setting REF-MC and height padding are necessary. Others with cast-on boxes, like IHC MOW, MDC oldtimers and others will require milling for obtaining box pad height. TANK Since early cars were just large wooden vats or tanks, rectangular or cylindrical, mounted on flat cars, they may be treated the same way. Later as demand for petroleum products grew larger, cylindrical metal tanks could no longer sit on top of floors. Open underframes with saddles permitted tanks to drop below floor level, with running boards around the periphery . An early 3600 gallon example had an LPF of 31' 5", LES of 29' 6 and a tank of 5' 7" OD " and 26' 0" length. This gives an ES-ES of 23" or PF-ES = 11 1/2" and an end sill to tank end of 21". A later 4500 gallon example had an LPF of 31' 5", LES of 29' 6 and a tank of 6' 1" OD " and 26' 2" length. This gives an ES-ES of 23" or PF-ES = 11 1/2" and an end sill to tank end of 20". A still later 5500 gallon example had an LPF of 32' 9", LES of 30' 10 and a tank of 6' 2 7/8" OD " and 27' 5 7/8" length. This gives an ES-ES of 23" or PF-ES = 11 1/2" and an end sill to tank end of 20 1/16". It is apparent that both tank length and OD could vary with respect to frame dimensions. Only one model, by AHM/IHC, matches the 3600 gallon closely. Its cast-on coupler box will require surgery to accommodate the 711 box. GONDOLE In general these appear to be modified flat cars. Often side posts were mounted in what appear to be flat car stake pockets. Although true hoppers existed, in classification, there was no division between them and gons. As late as 1910, most gons had drop-bottom doors, serving dual purpose. Initially the major differences, segregating bulk load, coal, coke, ore, sand and stone cars, were higher sides and shorter lengths. An early gon had an LPF of 35' 4 1/2", LES of 33' 1", inside length (IL) of 30' 9 1/2" and length over box (LOB) of 31' 7 1/2". ES-ES = LPF - LES = 27 1/2" and PF-ES of 13 3/4". EC-EC = LPF - LOB = 42" LOB - IL = 10" for 5" end walls and LES - LOB = 17 1/2" for 8 3/4" endsills. A slightly later one had an LPF of 37' 10 1/2", LES of 35' 7", inside length (IL) of 33' 0" and length over box (LOB) of 33' 7 1/2". The ES-ES = 27 1/2" and PF-ES = 13 3/4", but EC-EC = 51". end walls = 3 3/4" and end sills = 11 3/4". The major change seemed to be in end walls, which effected EC-EC and end sills. A still later car had an LPF of 40' 7 1/2", LES of 38' 4", inside length (IL) of 35' 5" and length over box (LOB) of 36' 4 1/2". The ES-ES = 27 1/2", PF-ES = 13 3/4", EC-EC = 51". end walls = 5 3/4" and end sills = 11 3/4". Again the major change was in the end wall design, without effecting end parameters. Since designs varied on different railroads along with heights, either the end sill or end corner may be select as reference, so REF-MC will depend on selection. HOPPERS Many of these were just higher and shorter variations of gons and may be treated a such. Most, lacking slope sheets, required hand shoveling to completely empty them. Some had small depressed hoppers at the center, below floor level to increase volume. These resembled clam shell types, but doors were usually hinged longitudinally. They were commonly called hopper- bottom gondole or coal cars. Some antebellum hoppers with slope sheets, were produced. One about 15' IL, four wheel, anthracite version, offered by Red Ball lasted into the 90's. Similar cars were used by the NYC and shorter 10' 4" IL cars were used in joint P & R and PRR unit trains. The drawbar face to end corner was about 12" for and EC-EC of 27 1/2" . While the face to end sill was about 8" for an ES-ES 19 1/2". Sizes seem to have varied considerably . A P & R, two truck version with hook & chain had an LOB = 22', 5" end sills and 5" dead-blocks. a chain with three 6" links and recessed hook with pulling point extending 2" past sill. This would yield approximately an ES-ES = 14", EC-EC = 24" and 4" between dead blocks, for the two usable links. A little later two truck, PRR car, had a length over faces (LOF) of 21' 11", LES of 20' 9" and LOB of 19' 9". This would yield a face to end sill = 7", ES-ES = 17 1/2" and EC-EC = 29 1/2" with a 6" end sill. Similar cars was also offered by Red Ball. Gould/Tichey offered an excellent, late truss rod ore car which is fairly typical of hoppers in this era and may pass as a hopper. With cast-on boxes, it will require surgery to mount 711's. Apparently saw tooth hoppers were introduced during the 80's with boxes and end dimensions similar gons at the time. Again a choice of reference must be made according appearance. HOUSE CARS (BOX, REEFER AND STOCK) These frequently deviated from the basic flat car designs. Due to height, here the most obvious judging location is at the corners or end posts. Spacing seemed to increase concurrently with car length. One early box car, with link and pin couplers, had an inside length (IL) = 27' 5 1/4", a length over end corners (LEC) = 28' 6 3/4", a length over end sills (LES) = 29' 10 3/4". With the standard 17 1/2" ES-ES, EC-EC = LES -LEC + 17 1/2" = 33 1/2" The same box car, with knuckle couplers, had an inside length (IL) of 27' 5 1/4", a 29' 10 3/4" length over end sills (LES) and 32' 2 1/4" LPF. But LEC was missing. End sill to end sill spacing and pulling face to end sill are: ES-ES = LPF - LEC = 27 1/2" PF-ES = ES-ES /2 = 13 3/4" Sheathing was 7/8" and corner post was 5" for a double sheathed, thickness of 6 3/4" . Adding two thicknesses at 13 1/2" to IL gives 28' 6 3/4 length over corners (LEC). Subtracting this from LES gives 16" or end sill was 8". EC-EC = LPF - LEC = 43 1/2" Alternately this could be found by adding the 8" end sill to PF-ES = 21 3/4". Twice this is EC-EC = 43 1/2". Apparently changing to knuckles increases spacing. A 33' 10 1/4" and a 35' 9 1/4" IL cars produced the same results. The only major difference in treating Stock and single sheath cars is that EC-EC will be measured over external end posts. Since IL is measured inside ice bunkers, refrigerator cars present greater problems, if LEC is not given. Measuring might be the only solution. An early car had IL = 33' 11 1/4", LEC = 35' 0 1/4", LES = 36' 4" and LPF = 38' 7 1/2" with 32' 2 1/4" inside bunkers. EC-EC = 43 1/2" and ES-ES = 24 1/2" with 9 1/2" end sills. Some box cars and other house cars lacked extended end sills, having buffers and striking plates mounted at end sheets. Furniture cars varied from usual box car practices. PASSENGER CARS Apparently all passenger cars had open platforms, including baggage and postal, until about 1892, when blind ends were introduced on some headend cars and enclosed vestibules were added for passenger convenience. Spacing was set at the platform end sills to permit access between cars and should be referenced there. Very little information is available for cars built much before 1870, which probably used hook and 3 link chain coupling. Possibly wooden dead blocks were used as buffers to reduce damage to platform endsills. Spacing was probably set at an easy stride in a long skirt. Passenger car lengths were usually measured over corner posts of the enclosed body, excluding platforms. Most were less than 40' or about 46' including platforms, making them usable on an 18" R. The only readily available Antebellum cars with typical radial roofs are the Mantua/Tyco civil war series. The older brass IMP and cast Alexander are rare. A practical best guess is shown in MANTUA/TYCO 36' PASSENGER CARS . Circa 1870, long sprung buffer beams were extended beyond sills to reduce jerky motions between cars. Although these could be fabricated, springing might be impractical . Not unlike those used in Europe for many years, round buffers appeared, but spaced only 11" from car centerline. Metal face plates with walkway extensions reduced gaps. Buffers and face plates were on sills, while couplers were below floor framing level, simplifying establishment of distances and mounting couplers. End sills usually tapered back for end clearance on curves. Since most models, except brass, used talgo coupler mounts, the only problems should be in setting mounting center and shimming to height for body mount .. Using link & pin, an early baggage, with long bar buffers beneath floor, had a length over corner posts (LOP), excluding platforms, of 40' 0", length over end sills (LES) of 46' 3" and length over coupler faces (LOF) of 47' 0". It is not clear, but this does not seem to account for end plate extensions, which appear to be from 1 3/4" to 3". ES-ES = 47' 0" - 46' 3" + 3 1/2 = 9" + 3 1/2 = 12 1/2". A later baggage had an LOP = 60' 0", LES = 66' 6" and LPF = 67' 3 1/2" for an ES-ES = 13". /An early coach had an LOP = 46' 6", LES = 52' 9" and LOF = 53' 6". ES-ES = 53' 6" - 52' 9" + 3 1/2 = 12 1/2." /A later coach had an LOP = 46' 6", LES = 52' 9" and LOF = 53' 6". ES-ES = 53' 6" - 52' 9" + 3 1/2 = 12 1/2." If the end plate extension were included, a 9" separation between plates seems reasonable. The ROUNDHOUSE (MDC) 50' OPEN PLATFORM CARS are very similar. After 1892, using knuckles, a baggage had an LOP = 46' 6", LES = 52' 5 3/4" and LPF = 53' 8 1/2". ES-ES = 53' 8 1/2" - 52' 5 3/4" = 14 3/4". It appears that round buffers were eliminated and metal end plates now included sprung buffers which were extended at floor level with top walkway plates to fill gaps between end sills. A coach had an LOP = 53' 8", LES = 59' 11 1/4", LPF = 61' 3 and length over buffers (LOB) = 61' 1 1/2"2. ES-ES = 61' 3" - 59' 11 1/4" = 15 3/4". BF-BF = 61' 3" - 61' 1 1/2" = 1 1/2". Around 1890 Barney & Smith, Pullman and others produced elaborate sleeping cars with narrow vestibules using diaphragms to protect passengers from the elements, while traveling between cars. Westwood, Westerfield and MDC offered models of these. Many other cars were converted to narrow vestibules, with 25" doors and diaphragms. Since they are the most visible judging points, here the reference should be the distance between platform corner posts (EC-EC). As above, the same class car had an LOP = 53' 8", LES = 59' 11 1/4", length over corner posts (LEC) = 58' 8 1/4", LPF = 60' 11 1/2" and length over buffers (LOB) = 60' 10". ES-ES = 60' 11 1/2" - 59' 11 1/4" = 12 1/4". BF-BF = 60' 11 1/2" - 60' 10" = 1 1/2". EC-EC = 60' 11 1/2" - 58' 8" = 27 1/4" Soon after, wide vestibules, with 29" doors and diaphragms, were introduced. The same class car had an LOP = 53' 8", LES = 61' 4 3/4", length over corner posts (LEC) = 59' 10 3/4" and LPF = 62' 4 3/4". ES-ES = 62' 4 3/4" - 61' 4 3/4" = 12". EC-EC = 62' 4 3/4" - 59' 10 3/4" = 30" This EC-EC is the standard used later for all 20th century passenger cars. BACK TO CLOSE COUPLING BACK TO METHODS INDEX |
| Browser -- Ibrowse V2.3 -- 2003
Text -- CygnusEd Professional V4.2 -- 1999 Drawings -- XCAD-3000 V1.1 -- 1992 Graphs -- Math-Amation V1.0d -- 1988 Rendering -- Image FX V4.1 -- 2000 Digital Camera -- Kodak DC25 -- 1998 Digital Camera 2 -- Kodak DC280 -- 2003 Scanner -- HP Scanjet 6200C -- 2000 HTML and mistakes -- BUDB -- 1931 |
