Fuel tenders became popular for helper service in Sheridan for two reasons.  First, there are no refueling facilities at the "roundhouse", so any refueling has to be done by a local fuel distributor or by sending the units to another location like Glendive or Laurel, MT.  Second, it allowed the railroad to purchase fuel at the least expensive location in the region and ship it to the helper district.  With a fuel tender in each helper set the locomotives could continue to run without a stop for refueling between their 92-day inspection dates.  Once a fuel tender is emptied, it is switched out of the helper consist and a loaded fuel tender is replaced between the locomotives.

The locomotives do not continuously draw fuel from the fuel tender.  Instead, pumps on the locomotives refill the fuel tank from the fuel tender once enough fuel is used out of the locomotive tank.  This keeps the fuel tank full and the most weight possible on the wheels to provide tractive effort.

Fuel tenders were not used only in helper sets though.  In 1987, they began running on main line freight trains and were usually connected to GP50s, B30-7As, and LMX B39-8 lease units.  The fuel tenders had the same advantages for through freight trains as they did for helper service - fewer stops and the best available regional price for fuel.  As other power became more prevalent, fuel tender use was discontinued in main line freight service.

In January of 2001, the BN SD40-2s disappeared from Sheridan helper service almost overnight and were replaced by BN SD60Ms and EMD SD60s.  At first, the BN SD60Ms ran in pairs without the fuel tenders, but eventually enough of the units were set up to run with a fuel tender splicing two units.  However, by the end of 2001, the fuel tenders were removed from service.  Reasons varied from a non compliant valve on the tanks, too much stress on the frames of the fuel tenders, and the extra car length preventing long coal trains from fitting in some sidings.

In May of 2002, the fuel tenders began to return to the helper sets.  This was most likely due to the high cost of buying fuel from a distributor in Sheridan and not directly from a refinery in Montana as is done now with the fuel tenders.  There was some work done to the existing fuel tenders and they were restenciled with new information and directions (see BNFT 32).  The fuel tenders are not used with every helper set, but usually a couple are running with them at any one time.

Not all locomotives are equipped to run with fuel tenders.  Those that are have fuel hose connections located on the front and rear of the units near the other multiple unit connections.  In the photo on the left, a yellow & blue spiral striped fuel hose is connected to the locomotive and laying behind the MU jumper.  This hose can be connected to a fuel tender or another equally equipped locomotive.

To connect or disconnect the fuel hose, or the socket cover, you pull on the handle while inserting or removing the hose.  The connectors are similar to standard hydraulic connectors with a groove around the hose end connector and spring loaded balls inside the fixed connector which lock into the groove.

This photo shows half of the connections on the end of BNFT 47.  On the left is the multiple unit (MU) socket with the EMD logo on the cover.  On the right is the fuel hose socket with the cover in place.  The other side of the fuel tender has the MU hoses.  The full view is shown on BNFT 47.

In front of the couplers are the yellow & blue fuel hose and the MU hoses.  Below the third step on the locomotive is the fuel line running back towards the pump and fuel tank.

Above the coupler on the fuel tender is the MU cable plugged into the appropriate socket.  The fuel tenders only have the MU connections on one side and thus if two fuel tenders are connected together they must be facing the same direction.