In the late 1960's, when the Santa Fe was looking at new motive power from Electro-Motive Division (EMD) and General Electric, the company found the purchase price of a new locomotive to be at least $150,000, and when options were added, the price far exceeded the base figure. At this time, the ATSF had determined that a minimum of 200 locomotives were needed to meet branch line and secondary mainline demands. With the staggering sticker shock staring the company in the face, the decision to determine if older power could be rebuilt to meet traffic demands began.

       The study to turn older power into a means to handle traffic needs began to focus on the 200-series EMD F-unit roster, and to determine if a complete overhaul was feasible, and if it was, what price per unit would each conversion cost. The target of the rebuild program was to produce a new rebuilt unit for approximately $60,000. However, when the CF7 project was fully in operation, the rebuilt locomotives were actually costing $40,000 per locomotive.

       When the decision was reached to utilize the 200-series F-units for rebuilding, the Santa Fe discovered two problems with them. The first was the fact the units were in desperate need of overhaul and repair. The class had literally millions of miles across the vast Santa Fe system on them. The second was the carbody of the F-units was totally unsuitable for any type of switching duty. The engineer and brakeman could not see the end of the train or where to spot cars without leaning out of the cab window. These facts would have to be dealt with in the new rebuild program.

       The ATSF determined the only way to complete the overhaul of the 200-series F-units would be accomplished by removing the carbody and transform each unit into a conventional road switcher, similar in profile to the EMD-produced locomotives of the later 1940's and 1950's - the GP7/9.

       Once the Santa Fe was committed to this rebuild program, it had offered the program to EMD and GE, however both companies flatly refused the project as they felt it could not be done. EMD and GE engineers were quick to point out that once the carbody was cut through and removed, the structural integrity of the unit would be lost, and the unit would suffer from a constantly sagging frame. Undaunted by the fierce engineering rhetoric from EMD and GE, Santa Fe continued to look for a facility which could handle this rebuilding program. The company received an enthusiastic reply from Mr. Charles W. Cramer, Superintendent of the Cleburne Shops in Texas, and the first F7, #262C was sent down for its conversion as well as an initial order of six units. This first rebuild would also determine if additional F-units would be converted.

Beginning of the Program - #262C / #2649

       Work on #262C began in the Fall of 1969. Over the next few months, the skilled craftsmen of the Cleburne, TX shops would transform the worn and tired F7 into #2649, the first CF7. Within the next eight years, 232 other CF7 locomotives would follow the prototype, and enter service on Santa Fe's vast system.

       ATSF CF7 #2649 was a unique locomotive among a unique class of units. It was the first CF7 out of the Cleburne Shops, however it was the experiment that established the pattern for other F-units to follow in the conversion process. The #2649 also had the only dynamic brakes ever placed on a CF7 locomotive. The dynamic brakes came from the long hood of wrecked GP7B #2788A which was around when this first CF7 was being put together, although seven inches had to be cut from the bottom of the hood in the location where the hood connected to the main frame and the running board in order for the hood to fit on #2649. Later units had long hoods fabricated from scratch by the highly skilled Cleburne shop forces.

       The #2649 also had smaller steps as compared to the rest of the CF7 class. Steps on the rest of the CF7s were enlarged to allow brakemen to enjoy better footing, and was found out by enlisting feedback from trainmen on the Santa Fe system. Other improvements were steps that were large and lowered, as well as properly placed grab irons which aiding in the safe operation of switching movements.

       The #2649 was also the longest in the rebuild program, as it was in the Cleburne Shops from October 1969 to February 1970. Another modification done on #2649 was the addition of deck plate steel. When the carbody was removed, the Cleburne craftsmen determined the side sills needed an additional reinforcement of the present 1/2" deck plate with 1.5" deck plate. After additional testing, the reinforcement was found to be excessive, and was not added to the following locomotives. It was found the side sills would be sufficient in strength, and not incur frame sagging.

       ATSF #2649 was officially unveiled to the media and the public on Friday, 13 March 1970, where it made its initial public appearance. In reality, the locomotive had been on the road for weeks where extensive testing had occurred. Once unveiled, the locomotive served the Santa Fe in regular road service, and was assigned as a local switcher at Clovis, NM, at least once in its life. Although the first completed CF7, and trailblazer for the program, #2649 ended up as a parts contributor for the rebuilding of two EMD F3 units for the Anthracite Historical Railway Society.

       06 Nov 2007 Update: Bryan Hartle tells the engine main generator, aux. generator, air compressor and several other minor components went into the rebuild of F3 #56. The trucks and traction motors are under F3 #57. The #2649's frame, cab, and dummy trucks were scrapped by Pollock, just north of Reading, PA after no one expressed an interest in the remains of #2649, and it had to be removed from a Conrail track that needed to be vacated. Mr. Hartle expresses to this day, the #56 still has a fine running engine. Thank you for the update Mr. Hartle!

About the Rebuilding Program

       Once the rebuilding program was underway, the production schedule itself fell into a regular rhythm. Two hundred and thirty-three locomotives were rebuilt from February 1970 until March 1978. The place within Santa Fe's roster for the CF7s began with #2649, and went in descending order to #2417. Santa Fe's CF7 rebuilding program terminated when there were no more EMD F units left on the roster to convert. There were 24 F units on Santa Fe's roster that did not undergo the CF7 program as they were subjects of wrecks, and it was determined these particular locomotives were not feasible to undergo conversion. Another side note to add to the CF7 program was in addition to F7 units, both F3 and F9 locomotives were converted as well.

       At the Cleburne Shops, the main conversion of F-units to CF7s took place in the Boiler and Coach Shops from 1970 to 1976, however in 1976, the Coach Shop caught fire, and burned. Since that incident, the Boiler Shop would remain the primary facility for the rebuilding program.

       The time of taking an F7 and converting it to a CF7 took an average of 45 days. This time takes into account the arrival of the F-unit at the shops to the final inspection and assignment back into the ATSF motive power pool. After each locomotive conversion was completed, each unit spent anywhere from 8 to 16 hours having electrical load tests performed, and after these were completed, each unit was taken out to the field for a run from Cleburne to Dallas, TX to Cleburne.

       The CF7 conversion program was considered a complete rebuild, as everything was redone on the original F unit, from rebuilding the trucks, to the construction of a new cab. The Cleburne Shops stripped each original F unit down to its stark frame, and then placed all of the rebuilt pieces back into the form of the CF7.

The Prime Mover of the CF7

       The choice of the prime mover was an important decision for the Santa Fe Railway. As far as the locomotive roster was concerned, Santa Fe's F7 locomotives utilized the EMD 567B prime mover. Specifically, the actual prime mover was the EMD 16-567B, which was a sixteen cylinder engine. However, most CF7 locomotives received the EMD 567BC engine, the exceptions being #2649 and #2648, which were fitted with the EMD 567B engine block. For its part, the EMD 567BC was an upgrade where the B head was placed upon the C liner. EMD designed the C liners to be cooled by water jumpers, so the upgrade would be relatively inexpensive.

       Santa Fe's choice to stay with the EMD 567 engine proved to be a particularly wise one. The engine had a long and dependable history, being first developed in 1397, and continued production until 1966. So what does 567 actually stand for? The designation originates to the bore stroke of 8.5" bore with a 10" stroke for a displacement of 567 cubic inches.

       When rebuilding the engines within the CF7 program, the prime mover was completely removed, and totally dismantled. Everything from cylinder sleeves to valve springs were replaced on the engine block, and once the block was completely reassembled, it was then installed back onto the frame.

       The 567 engine used within the CF7 program produced 1,500 horsepower, which was the same amount when the engine was housed within its original confines of the F7. There were discussions within Santa Fe during the early part of the CF7 program to boost the available amount of horsepower, however after reviewing where the CF7 locomotives would be operating, branch line service, and switching, it was felt the 1,500 horsepower rating for sufficient. One CF7, #2452, was tested with a 645 engine, which boosted its horsepower from 1,500 to 2,000. More CF7s were not fitted with the 645 engine, as the Santa Fe had more spare parts around its system for the 567 engine, and further use of the 645 engine within the CF7 program was dropped.

       The newly constructed CF7's introduced some safety features related to its prime mover. The engine would shut down if its top speed of 72 m.p.h. was exceeded, and would also be shut down if the engine exceeded 925 r.p.m.

Rebuilding the Trucks

       The trucks were also completely rebuilt on each CF7 that passed through the Cleburne Shops. The trucks were removed from the incoming F unit, and the generator and electric traction motors were then themselves removed, and shipped to Santa Fe's San Bernardino Shops to be rewound. The generators themselves were upgraded from D12B to D14, and the traction motors were redone from D27 and D37 specs to D77 specifications. The first set of CF7s had their trucks painted black, however as the program progressed, the standard was set to paint the trucks silver.

       The CF7 utilized the very popular Blomberg truck. It can be identified by the prominent outside spring hangers which permit a better ride during side to side movement. An additional advantage of this particular truck was its ability to widen its spring base from 56 to 96 inches. The truck is named for Martin Blomberg, who joined EMD in 1935, and EMD introduced the truck a year later in 1936.

       An interesting note on the CF7 truck rebuilding subsection was the fact that the trucks were reassembled upside down. This was done for safety reasons, as well as easy of assembly. When the rewound traction motors were returned from the San Bernardino Shops, and installed, the completed, and rebuilt, truck was then turned right side up, and installed into an awaiting CF7 assembly.

CF7's Unique Side Sill

       Besides the cab, one of the other distinctive features of the CF7 was the side sill. The side sill's job replaced the car body, and thus provided support for the locomotive frame once the original F unit body was removed. The side sill changed throughout the CF7 program as some were open, while others were enclosed.

       Other than the traction motors going to the San Bernardino Shops, the only other section not build at the Cleburne Shops was the side sill, which was manufactured in the Topeka Shops. The early locomotives through the CF7 program were rebuilt with an open sill manufactured of Tri-10 steel. Later CF7s used softer steel and had the sill filled with gussets to provide additional support.

       The sill was originally a 24" I beam, to this was added a three-quarter inch camber, which ran the length of the frame. The purpose of the camber was to give additional strength to the frame, and also aid the frame to support the prime mover. The frame was also strengthened by a dutch plate.

Those CF7 Windows

       Before the window design on the CF7 was standardized, there were several phases throughout the initial stages of the rebuild program. Since the original reason for even having the CF7 was to save the ATSF money, the F unit window, with its older style crank-type, was left in place during the initial CF7s, which utilized the round F unit cab roof. During the use of the initial sets of CF7s, the crank window was found to be too small and cumbersome during switching, and thus later CF7s had slide mounted windows installed.

Electrical Systems

       At the outset of the CF7 program, the first couple of units kept their original electrical cabinets until it was noted that the cabinets themselves did not have the same dimensions. Since this discovery, the Cleburne Shop forces found it necessary to fabricate electrical cabinets for the remainder of the program.

       The cabinets and its associated wiring were constructed and brought up to the technology of the time. Of note was the disuse of the original F unit electrical harness, as new ones were used in its place. With the upgrade in electrical capability, each CF7 locomotive was able to "m.u." with other locomotives because of the installed 27 pin multiple unit electrical connections.

       One other feature installed into the CF7s by the Cleburne Shops was a selector switch which allowed crews to choose between settings for either switching or road service. While the switch was placed in the switching position, the engine could be loaded very quickly for easier switching capability. However, when in the road service position, the switch allowed the prime mover to load up slowly, thus giving crews an easier starting locomotive, and thus help eliminate and prevent frustrating knuckle breaks. Although when first installed, this load switching ability of the prime mover later proved to be a source of frustration with the units, as the switch was found to be often faulty, and kept the prime mover in "road service" mode.

Cabs: Round vs. Angle

       Since the original reason for the Santa Fe to embark on the CF7 rebuilding program was to save money, the original batches of CF7s were released from the Cleburne Shops with the rounded roof cabs, as it was thought by preserving the contour left over from the F unit roof, money could indeed be saved.

       However, as the program progressed, it was found the round roof would not save money for the ATSF because the doors associated with this rounded-roof cab had to be custom fitted. CF7 #2638 was the first locomotive to refitted with the angled cab and fitted with standardized doors, and thus saving Santa Fe 50% of the cost of custom-fitted doors found on the original units.

       There always has been talk that the angled cab is known as a "Topeka Cab", and this was because the Topeka Shops "rubber-stamped" the changes made throughout the CF7 program, however all of the angled-cabs were indeed fabricated by the Cleburne Shops, and the Topeka Shops had no input with regards to the origination, or fabrication, of the angled cab.

       The new, large cab allowed a Santa Fe crew of three, comprised of the engineer, fireman, and head brakeman, room to complete their work. The Cleburne Shops also brought new innovation in the form of adding side mirrors to both sides of the cab so both sides of a train could be monitored.

       The new angled cab also allowed Cleburne Shop forces to provide Santa Fe crews with better sound insulation, as they added a lead plate, and foam insulation installed in the roof of the cab to suppress noise and vibration for train crews. It is interesting to note that the Cleburne Shops had measurements taken from the LaJunta, CO roundhouse, which contained the smallest height doors on the ATSF system, to insure the CF7 could be used everywhere.


       Like other parts of the original F unit, the CF7 rebuild program also recycled the horns. They were refitted with new diaphragms and were placed on outgoing CF7 locomotives as they were needed. This however meant locomotives leaving the rebuild program contained a variety of horn configurations, ranging from single chime to five chime.

       There was an interesting aspect with regards to the horn placement within the CF7 program. The placement and calibration was a project that took place over a three month time period, as there were many aspects to process such as decibel level, which lead to the movement of the horns, originally placed at the back of the cab early in the rebuild process, to the front of the cab. This was done in order to provide for the safety of the crews' hearing.

Fuel Tanks

       Since almost every part of an incoming F unit was used on the resulting CF7s, the fuel tanks can be included as well. There were several steps with regards to the fuel tanks within the CF7 rebuilding program. The first step was to empty and steam clean the tanks. The next step was then to mate the tanks to the frame. Now on the original CF7 rebuilds, the tanks were simply bolted onto the frame. However when these units were used throughout the Santa Fe system, the bolts failed, and several of these units actually dropped their fuel tanks. After this problem was investigated, the Cleburne Shops made a solution, which was to strengthen the bolts by adding a fuel rack hanger, and thus prevented the fuel tanks from failing.

Exhaust Stacks

       Another aspect which changed throughout the CF7 program was the locomotive's exhaust stacks. The first batch of 36 units were manufactured with a twin exhaust stacks. This system did not prove well while these units were out on the road, as fires developed within the units when they were assigned to dry climates. Also, the spark arrestors added to the twin stack system were found ineffective, and later removed. In order to fix the problem, the Cleburne Shop force obtained the original four stack exhaust system from the Farr Manufacturing Company. With this system, the shop forces were able to duplicate the Farr system for only 1/3 of the price, and from that point forward, all of the rest of the CF7s were equipped with the four stack exhaust system.

Air Conditioning

       The Santa Fe Railway was the first railroad in the United States to add the comfort of air conditioning to its locomotive fleet, and the inclusion of this feature can also be found on the CF7 locomotives.

       Although there has been some discussion of whether all CF7s had air conditioning, shop forces were quick to point out ALL CF7 locomotives were equipped with air conditioning. The original batches of CF7s with the round roofs were rebuilt with a Mark IV air conditioner, which was manufactured in Dallas, TX. This unit was placed inside the cab across the front windshield. The a/c unit had a compressor, which was in turn powered by an air compressor shaft. In order to comply with better standardization, as these early units were cycled back through to receive their angled cabs, they too received the exterior, box-like air conditioner units found on Santa Fe locomotives.

       Later in the program, CF7s were equipped with air conditioning units from the Prime Corporation, as well as the Vapor Corporation, which were standard on the angled-cab edition of the newly rebuilt locomotives. The angled cab, in addition to holding the a/c unit, also had the horn, and the antenna.

Crew Comfort

       One of the topics not found to be discussed in detail was the crew comfort station, found in the short front hood of the CF7.

       Although equipped, train crews seldom used the station because of the cumbersome way one had to enter and exit the short hood door. If a crew member did use the station, he was not quite "alone". To his right, one had the front truck and its associated blower motors on the right, and to the left were the sanders and the skin of the short hood.

The Hoods

       The short hood of the CF7, sometimes compared to a GE short hood, was completely fabricated by the Cleburne Shop forces, and was a customized section on each CF7 going through the rebuild program. The reason was the space left after removal of the F unit nose, was only the space of a typical GP7 short hood.

       In order to construct the short hood, the Cleburne Shop forces manufactured the hood around collision posts, and to add protection for the train crew, eight inch steel I-beams were mounted to the frame in a vertical fashion, and then connecting one-half-inch wall tubing was welded to the collision posts - forming a protective web.

       Although #2649 had an EMD hood, all of the other CF7s had their long hoods custom manufactured by the skilled shop forces in Cleburne. The shop crews set up two manufacturing jigs in the Boiler Shop which aided in the construction of the hoods. By the time the hoods were completed, they had all the electrical connections installed, including the cooling fans. All that was needed was to attach the completed hood to the frame, and then make all needed connections.

Around the Santa Fe System

       CF7 locomotives could be found throughout Santa Fe's vast railway system. They could be found m.u.'d to other locomotives in consists hauling mainline freight, however most worked as switchers, and performed duties hauling local freight. One specific place the CF7s came to call home was Carlsbad, NM, working on the potash trains.

       CF7 locomotives were often found m.u.'d to old, cabless F units which had been turned into road slugs. CF7 locomotives #2612 through #2625 could be found mated to road slugs and working on the potash trains between the communities of Carlsbad and Clovis, NM. The CF7s were also equipped with RCE, and a typical potash train would involve two to three sets of CF7s and slugs.

Closing the Era

       In the mid-1980's when the proposed merger of Santa Fe with the Southern Pacific came into view, there was a new paint scheme introduced on the ATSF, the "Kodachrome". However, no CF7s were painted in this possible merger scheme, even though Santa Fe had contingency plans to renumber its CF7 class from 2649-2417, to 1131-1000. However the merger was denied, and the CF7s were already leaving the roster for shortlines. The first set was sold off in 1984, and the rest were sold in 1987. The CF7 era on the Santa Fe had arrived at its conclusion.



Width: Length: Height:
Over side sills 9' 11" Truck centers 30' 0" Over pilot 4' 9"
Over cab 9' 10" Over pilot plates 48' 6" Over side sill 5' 3"
Over short hood 4' 3" Over couplers 52' 0" Over long hood 13' 6"
Over long hood 5' 0" Over cab roof 14' 5"


Prime Mover 16-567BC Truck Type B-B Weight 249,000 lbs.
Length 48' 6" Drivers 40" Dynamic Brakes None
Width 9' 11" Gear Ratio 62:15 Main Generator D14
Height 14' 5" Top Speed 65 mph
Fuel Capacity 1,309 U.S. gallons Traction Motors D77 Horsepower 1,500



  • CF7 Locomotives: From Cleburne to Everywhere
         By Cary F. Poole
         The Railroad Press. 1997


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