Welcome to the BNSF B23-7 in Detail website. Here one can learn the history of the BNSF GE B23-7, as well as take a look at a prototype B23-7 from highly detailed, highly specific photos, provided by ATSF modeler, Eric Goodman.

      Enjoy your visit.

History of the B23-7

      General Electric (GE) introduced the B23-7 locomotive, successor to the U23B in September 1977. In 1976, GE had introduced the new Dash 7 series where the application of technology and carbody changes were made to existing products. In comparison to the U23B, the B23-7 was of equivalent horsepower, however the frame was extended by two (2) feet. And as was standard among other Dash 7 models, there was an outward bulge along the long hood just ahead of the radiator section. This extended hood section was to allow an elevated, and angled, oil cooler. In the U23B design, the oil cooler was vertical and at fllor level. In the B23-7, the angling of the oil cooler allowed it to drain, and thereby help reduce the possibility of damage in the winter if the locomotive was shut down. The B23-7 also was delivered with floating bolster trucks, unless a railroad provided trade-in trucks.

      The first order of B23-7 locomotives for the Atchison, Topeka, and Santa Fe arrived in April and May 1978, and were placed in the engine roster at 6350-6363, and rode standard floating bolster trucks. The second order arrived a year later between April and June 1979, were placed in the engine roster at 6364-6373 and rode floating bolster trucks, while the other half of the order, placed in the roster at 6374-6389, rode AAR type "B" trucks off traded-in U25Bs (numbers 6600-6615). Both the first and second order of Santa Fe B23-7 locomotives had nose-mounted cab air conditioning and were geared for 74:18 running. In April 1980, Santa Fe ordered fifteen more B23-7 locomotives from GE, and placed them in the roster at 6390-6404. This order rode on the floating bolster trucks.

      The final order of B23-7 locomotives for the Santa Fe was in December 1984, after trading in fourteen U23B locomotives (roster numbers 6301-6303, 6306-6308, 6310, 6312, 6320, 6324, 6331, 6339, 6341, and 6346). The last order was placed in the roster at 6405-6418 and rode on the AAR type "B" trucks from the traded-in U23B locomotives. The third and fourth order of B23-7 locomotives included cab roof-mountd air conditioners, as well as 83:20 gearing.

      All of Santa Fe's B23-7 locomotives were delivered in the yellow and blue warbonnet paint scheme, and all had a plated nose light receptacle when delivered, except for units 6405-6418. Santa Fe utilized this type of locomotive in the flatlands of the Eastern and Western Lines. The units were used in mainline freight pools, as well as secondary pools and local power.

      Santa Fe sent this class of locomotive to undergo remanufacturing by the skilled craftsmen at the famed San Bernardino, California, Shops. Santa Fe upgraded the horsepower of some of the units to 3,000 horsepower, and this was indicated on some units by a "3000 HP" letter marking, placed under the side cab numbers. These B23-7's were at one time placed in the roster behind SF30B #7200, and they became the 7201-class, and resided in the roster from 7201-7216 (original numbers were 6366-6370, 6372-6379, 6389, 6393, 6395). However by the middle of 1989, the units were notched down to 2,250 horsepower and placed back into the roster to form the 6350-series. This was done because of GE's objection over the increased horsepower rating during maintenance negotiations with the ATSF. Other modifications to the B23-7 pool were the blanking of classification lights, high headlight removal and replacement with nose headlights, as well as the additiona of rotary beacons.

      During the merger fever between the Santa Fe and Southern Pacific in the mid-1980's, nine B23-7 locomotives wore the short-lived "Kodachrome" paint scheme. The locomotives were 6354, 6365, 6373-6375, 6380, 6388, 6396, and 6404. With the denial of the merger, all of these units were gradually repainted back into the yellow and blue warbonnet paint scheme. Today all of the 69 B23-7 locomotives are still in active service.

      BNSF #4245 was originally Santa Fe #6388, and was built in June 1979, with frame number 42434. The locomotive was delivered in blue and yellow warbonnet and rode AAR-B trucks. It wore the SPSF 'Kodachrome' paint scheme from 31 July 1985 through 24 July 1986, and then repainted back into the blue and yellow warbonnet paint scheme. The locomotive continues to serve on the BNSF Railway, and was placed into its current roster spot, #4245, on 28 January 2000.


Other B23-7 sites

  • BNSF B23-7 Index at TrainPix.com by Charles Biel
  • BNSF B23-7 #4245 Photo at TrainPix.com by Charles Biel
  • ATSF B23-7 Index at TrainPix.com by Charles Biel
  • ATSF B23-7 #6388 Photo at TrainPix.com by Charles Biel
  • ATSF 6000-series Locomotives at Fallen Flags



    Prime Mover 12-7FDL Truck Type B-B Weight 265,000 lbs.
    Length 61' 2" Drivers 40" Dynamic Brakes SLT
    Width 10' 2" Gear Ratio 74:18 Main Generator GTA-11
    Height 15' 4" Top Speed 65 mph Alternator GY27
    Fuel Capacity 2,900 U.S. gallons Traction Motors 4-GE752 Horsepower 3,250


    ALL photos are copyright by Eric Goodman and cannot be used without his permission.
    Page layout and Graphics are copyright © 2005 by QStation.org