bolster. In most cases, the locomotive is articulated over the span bolster. The Union Pacific's M-10002 diesel streamliner and New York Central's T-Motor third rail electric locomotives are examples of this type. This arrangement also includes locomotives made of two permanently coupled B-B units, such as some EMD FT units which had a solid drawbar connecting two units instead of the typical couplers. B-B-B-B "B-B-B-B" means there are four trucks. Each truck has two powered axles. The locomotive frame must allow for significant side play to be provided to the center trucks. B-B+B-B+B-B "B-B+B-B+B-B" means that the locomotive has six trucks. Each truck contains two powered axles. The only known locomotives to have this configuration were the two EMD TR3 locomotives made of three permanently coupled B-B units, which had solid drawbars connecting the units instead of the typical couplers. C "C" means there are three powered axles under the unit. They are not articulated relative to other parts of the locomotive. This arrangement is only used on very small locomotives (e.g. the PRR B1). This arrangement is sometimes referred to as 0-6-0, the Whyte notation equivalent. C-B "C-B" means there are two trucks. The "C" truck is under the front of the unit, and has three powered axles. The "B" truck is under the rear of the unit, and has two powered axles. The Japanese DE10 and DE11 locomotives use this wheel arrangement. C-C "C-C" means there are two identical trucks. Each truck has three powered axles. Examples include the EMD SD (Special Duty), GMD GF6C, EMD GM6C, PRR E44, GE E60, Virginian EL-C and GE Evolution Series units, except the ES44C4 and ET44C4 which use the A1A-A1A wheel arrangement. This is a currently popular configuration used in low-speed, high-weight applications, such as unit coal trains. General ("manifest") freight trains also use C-C locomotives. See also Co-Co. An American colloquialism of "C-C" is "Six axle". 1-C+C-1 "1-C+C-1" means there are two sets of articulated axles under the unit. Within each of these sets, there is a truck with one idler axle, and inboard of it are three powered axles. Two of these articulated sets are placed back to back and connected by a hinge. The PRR FF1 and FF2 electric locomotives used this arrangement. 2-C+C-2 "2-C+C-2" means there are two sets of articulated axles under the unit. Within each of these sets, there is a truck with two idler