As of 2001 the General Electric C44s are the BNSF's most powerful and newest locomotives (2001). The railroad has approximately 1400 of these locomotives and another 500 on order. Some specs of the C44s are:

• Horsepower: 4400
• Length: 73'2"
• Height: 15' 10"
• Width: 10' 3"
• Weight: 415,000 lbs.
• Continuous Tractive Effort: 105,640 lb.
• Maximum Speed: 73 mph
• Maximum Dynamic Braking Effort: 74,670 lb.
• Wheel Diameter: 42"
• Gear Ratio: 83:20
• Fuel Capacity: 5,000 gal.
• Engine: 7 FDL, 16 cylinder with EFI
• Engine RPM at full throttle: 1047

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C44 Fuel Use & Horsepower by Throttle Position

Throttle	Gal per Hr	Hp/Gal/Hr	Horsepower	Hp %max	=Model
8	210	21.4	4509	100%	C44 (4400)
7	151.8	24.1	3660	81%	SD45 (3600)
6	128.0	22.9	2940	65%	SD40 (3000)
5	103.5	21.4	2220	50%	GP30 (2250)
4	80.4	19.2	1550	34%	SD7 (1500)
3	56.5	18.4	1040	23%	SW1000 (1000)
2	39.6	12.5	500	11%	SW1 (600)
1	17.8	11.2	200	4.40%
Idle	3.6
Low Idle	2.7
Dynamic	2.7-10.2

Note 1: Notice that the Hp increases by 150% from throttle 1 to 2 and by 100% from 2 to 3. These huge increases make yarding trains at 10mph difficult. You must either constantly move the throttle up & down to maintain 10 mph or else apply independent brakes and work the power against the brakes making them hot. Perhaps GE had something with the 16 notch throttles on the 1960s era U25Cs.
Note 2: Hp/throttle figures are from actual C44 BNSF 4795 computer values.

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C44 BNSF 5320 Engine RPMs High Idle occurs for a period of 30 seconds every time you move the throttle from notch one to Idle.

Hi Idle	717
Idle	335
Throttle 1	577
Throttle 2	717
Throttle 3	992
Throttle 4	992
Throttle 5	992
Throttle 6	992
Throttle 7	992
Throttle 8	1047

Dynamic 1	435
Dynamic 2	435
Dynamic 3	435
Dynamic 4	435-577
Dynamic 5	577
Dynamic 6	717
Dynamic 7	717-885
Dynamic 8	885

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C44AC

The BNSF has only three of the AC traction versions of the C44. Loco numbers 5600-5602.

The table below shows the Tractive Effort readings taken from the engineer's TE meter at various speeds. If you multiply the TE times the speed (in ft/sec) then divide by 550 (definition of a HP) you can calculate the HP. Since the diesel engine developes 4400 HP and the TE x Spd figure is about 4100 HP this means the overall "transmission" efficiency is about 93%.

The table also shows the Main Alternator Volts and Amperage. By multiplying those two numbers to get the watts and then dividing by 746 (definition of a HP) you can calculate the HP output at the main alternator. This value comes out to about 4240 HP. That means the main alternator is about 96% efficient. Since the overall transmission efficiency is 93% this means the AC invertors, AC traction motors, and the gearing lose about 3% of the available power.

C44AC in number 8 Throttle

Speed	TE meter	Main Alternator Volts	Main Alternator Amps	HP based on TE & speed	HP based on Volts x Amps
10	.	.	.	.	.
15	100,000	862	3671	3999	4241
20	77,000	1073	2969	4106	4270
25	61,000	1340	2360	4066	4239
30	51,000	1350	2340	4079	4234
35	44,000	1350	2350	4106	4252
40	38,000	1350	2324	4053	4205
45				.	.
50				.	.

Created 08-18-2001
Updated 12-02-2002