Nickel Plate Road Class S-2 2-8-4 Berkshire Steam Locomotive (Prototype Info)
*Image used with permission of NKPH&TS 749 in the late 1950s, many S-2 Class seem to have lost their headlight visor after '57.
In January and August of 1944 the New York, Chicago and St Louis Railroad (Nickel Plate Road) placed an order with the Lima Locomotive Works of Lima Ohio for another set of 2-8-4 'Berkshire' type Steam Locomotives to be patterned in the proven Advisory Mechanical Committee 'Superpower' design of 1934.
This group of locomotives were a major step above previous AMC 2-8-4 deliveries to the Van Sweringen roads and incorporated a number of new features which made them worthy of their own class designation, becoming class 'S-2'.
The locomotives are incredibly impressive from an engineering point of view. Standing 15' 8" tall the class has a tractive effort of 64,135 Ibf, a working capacity weight of over 400 tons, a top speed of over 80 mph, Elesco Superheater and Baker Valve Gear. The driver diameter is 69" which is perfect for high speed mixed traffic running or slowly starting a loaded freight train.
A book can be written on the differences from other AMC/VS 2-8-4's, but one of the most standout and important was the employment of state of the art Commonwealth Cast Chassis' on the locomotives. This feature gave remarkable structural integrity and allowed a better ride than previous models. The locomotives also had roller bearings on all drivers and the lead pilot truck, coil springs placed above the rear drivers and improved sand dome piping. The coil springs worked in addition to the classic leaf springs employed on the forward drivers and are believed to be what contributed to the smooth ride that crews reported compared to earlier classes of the S series 2-8-4.
Locomotives were fitted with a Nathan 4000 Injector beneath the engineers (right hand) side of the cab with a lever on the cab floor just to the left of the engineers seat. This is a trademark of NKP Berks and is featured on the Cardinal River Models S-2 model.
The counterweights are known for their large size on these locomotives and the rear counterweight extends 6 inches from the surface to balance the weight conveyed from the main rod onto the rear side rod and driver. The rear side rod branches from the center of the main rod into a unique "Forked" arrangement.
For the August 1944 order the S-2 series began delivery from LIMA with the famous Nickel Plate Road numberboard arrangement. (All locomotives had numberboards by the late 40's).
The locomotives were delivered with a single Pyle National steam driven turbogenerator on the rear fireman's (left hand) side of the boiler above the firebox. Beginning in the early 50's the locomotives were equipped with oscillating Mars lights from the Mars Signal Light Company of Chicago Ill. This gave a larger electrical load and to meet demands a second turbogenerator was installed just ahead of the original. Thus, the locomotives now ran with two turbogenerators on the firemans side. The Mars lights were highly effective and all locomotives were outfitted with them by the end of 1953. The wiring for these Mars lights came from the firemans side of the locomotive (where the smokebox hinges) and a new squarish conduit arrangement was built across the upper smokebox door.
In the early 50's developments in radio technology allowed railroads to economically employ radios in their daily operations. The Nickel Plate Road believed in the use of radios and began to equip many of the S-2 class with large radio receiver boxes mounted atop the tender rear deck. The radios were either supplied by Bendix or Westinghouse and the boxes sported a hexagon top grounding plate with an antenna. Now there was a double set of conduit lines which ran from the radio atop the engineers side of the tender to connect to a junction box behind the cab. The radio equipment demanded a substantial electrical load that the original two turbo-generators could not meet and necessitated the forging of a new mounting bracket, this time on the engineers side of the locomotive directly opposite the original Turbogenerator placement. There is where a large dual unit Pyle-National Type K2TA-5, 500 VA, 117 VAC Turbo-Alternator was placed to power the new radio equipment. This changed the appearance of the S-2 Class and it has been thought by many the Turbo-Alternators were standard Turbogenerators and even has been documented in literature. Only locomotives equipped with the radio units received these Turbo-Alternators.
A feature of the S-2 Class which commonly inspires questions from railfans is the small cylindrical apparatus to the immediate forward right of the smokestack. Dubbed a 'can' this is the air compressor exhaust line water/vapor separator. The device allows some water to be recovered from exhaust steam after running through to drive the airpumps on the locomotive. 759 had another installed opposite the original during the excursion career and still wears it today.
A careful eye would notice that some locomotives had a variation between steam domes when compared side by side. Due to modifications with the dry pipe a 4" taller steam dome was ordered by the engineering department for placement on select locomotives. This came rather late in the career of the berks and only so many S-2's were equipped with the larger dome. The initial plan for Nickel Plate however envisioned all S-2 class to have the taller dome installed. In addition to its slightly taller stature, this dome can be spotted by having a steeper contour to the upper curve than the original and a flatter surface.
New from Lima, all the Nickel Plate 2-8-4's were equipped with a Franklin Precision Screw Reverser with an accompanying steering wheel in the cab just in front of the engineers seat. This piece of machinery was very effective in road service but it was found that sometimes in operations where a locomotive would need to constantly change directions (such as on a local, pickup/set off run) on occasion the reverser would lose its placement and spin the in cab wheel which could lead to injury. Therefore, it was decided in the early 1950's to refit many of the 2-8-4 locomotives with the ALCO Power Reverse. This is an air operated reverser and has an accompanying small pill shaped air cylinder offset and below the engineers side center air reservoir. Part of the refit did away with the in cab steering wheel and an injector like lever took its place. The ALCO Power Reversers performed very well and if steam was not retired its likely all the S-2 would have been refitted. The ALCO Power Reverse can easily be spotted on the engineers side of the locomotive just above the rear two drive wheels and sitting in a horizontal slant. New larger mounting plates were also cast for the mounting of the upgraded reversers. Regulations set in place from a complaint regarding the Brotherhood Of Locomotive Engineers and Brotherhood Of Locomotive Firemen stated that air operated power reversers should have a suitable steam connection to enable continued use in the event of air failure. Both 759 and 765 were upgraded with the ALCO Power Reverser.
The S-2 Class were equipped with steam and signal lines for passenger operations and pulled plenty of troop trains in the 40's and Korean War era of the 50's. The S-2 have been spotted on regularly scheduled Nickel Plate Road passenger runs. Something that puzzles scholars and was not well documented is that only a few locomotives were delivered with passenger lines however 755 (not being one of them) in Conneaut Ohio has all the passenger steam/signal equipment installed under its tender. This means that the NKP may have installed the steam/signal lines on more members of the class than initially specified - or - that the NKP (like many roads) swapped tenders around. Regardless, it cannot be denied that we have proof a locomotive not documented to be available for passenger service is fully equipped to tackle such service. This is great for modelers as you can prototypically run an S-2 on any period passenger train and be excused by most fellow enthusiasts.
Some of the locomotives were delivered with ATS (Automatic Train Stop) gear on the engineers side of the tender and the rear axle of the forward truck was equipped with a pickup shoe. This equipment was required on locomotives that operated on the West End of the Nickel Plate Mainline west from Bellevue to Chicago.
Locomotives were fitted with a wooden 'Push Pole' on the engineers side of the tender right above the rear truck and a 'Switching Chain' on the firemans side of the tender above the forward truck and draped on hangers.
The Push Pole could be removed and was used to assist in switching cars in awkward situations. This was HIGHLY dangerous and many railroads forbade its use. It is quite remarkable the NKP S-2 kept their poles till retirement. 765 still has the pole mounted on the side today. The round indents seen on the end of locomotives and cars of the era are where the pole was usually balanced to be used in its intended service.
The Switching Chain is similar to that used on modern diesel locomotives and is primarily used to tow a car into a siding if there's a broken knuckle. Could also be used in switching acts, and was certainly safer than the pole.
The Nickel Plate Road believed heavily in its group of 80 2-8-4 locomotives and foresighted their use into the 1960's. However as diesels came and changes to the steam industry took place it was deemed more economically feasible to retire the class and store them in operable condition. Many of the S-2 Series had Class III overhauls in the latest of the 50's, and this would have enabled them to be ran well into the 70's in revenue service. It took quite a while for the NKP to decide on scrapping their Berkshires.
It is well known the S-2 series are among the last steam locomotives to be ran in North America. Enthusiasts from far and wide made the trek to Nickel Plate rails to get a glimpse of the hotshot freights running at 80 or higher behind an S-2. The S-2 Class is truly timeless and will never be forgotten. Groups like the Fort Wayne Railroad Historical Society certainly make sure of that.
759 was resurrected in the late 60's to begin pulling steam excursions and was the first S-2 to be brought back after retirement. In the 70s a few modifications such as auxiliary valve oil reservoirs for the lubricators above the valve gear on both sides of the locomotive and an extra airpump steam exhaust water vapor separator (as mentioned above) were installed. The locomotive held the honor of pulling quite a few prominent excursions, not least of which being the Golden Spike Centennial Limited where 759 traveled as far west as Nebraska and wore a blue adornment primarily on the tender side. 759 also held the honor of pulling the last revenue operation of the Norfolk & Western's premier passenger train, The Pocahontas. For this latter run 759 wore Norfolk And Western Lettering on the tender sides. Today 759 resides as a premier exhibit at the Steamtown National Historic Site in Scranton Pennsylvania.
765 is the other famous member of the S-2 class and has been a most prominent excursion loco since the end of the 20th century. Resurrected in the late 70's, 765 has led a very celebrated career at the helm of excursion and "extra" trains. 765 has powered a few New River Train excursions in West Virginia's storied New River Gorge, worn disguises to pay homage to other roads, and was the featured locomotive on the Norfolk Southern Employee Special of 2012. Today 765 resides in Fort Wayne Indiana in operating care of the Fort Wayne Railroad Historical Society pulling annual excursions on the Indiana Northeastern Railroad.
There is a lot more to be said and as time permits this article will be updated to include more.
The Cardinal River Models S-2 2-8-4 Steam Locomotive Model has been designed with every single feature outlined in this article.
*765 during the 1990s in the New River Gorge of WV. Photographer Credit Jesse J. Smith