Train Makeup

Railroads define various restrictions on train makeup. These can be attributes of the entire train - length, weight, HP per Ton - or on the arrangement of locomotives and cars within a train.

BNSF

Length

Description	Length (ft)	Distance (ft) between DP consists
Non-DPU	10,000
One DPU consist, Intermodal		10,000
One DPU consist, other		8,500
Multiple DPU consists	13,000	6,500 between each consist

Locomotives

Trains are limited in power by Rated Powered Axles (RPA). BNSF system instructions (as of 2010) allow for two possible DPU configurations:

• One DPU consist, at least halfway through the train (including placement at the rear-end)
• Two DPU consists, with one mid-train consist (within 20 cars of the middle of the train), and one rear-end consist.

When using DPU, the total Rated Powered Axles of the leading consist cannot exceed the RPA of remote consists by more than 16.

Empty bulk trains are limited to a maximum of 9000 HP, and at least one locomotive must be active in each DP consist, meaning that empty bulk trains running with DP must have one locomotive active at the head end, and one active at the rear.

Description	Head end RPA	Mid train RPA	Rear end RPA
Intermodal	48	24	16
Manifest	42	24	16
Empty Bulk	16	8	8
Loaded Bulk	32	40	24

Rated Powered Axle listing

Locomotive	RPA
All SW/GP units not otherwise listed	4
GP60M / GP60B	5
All SD units not otherwise listed	6
SD60 / SD60M	7
SD70M	7
SD75M	7
C40-8	7
C44-9W	8
ES44DC	8
AC440CW	8
ES44AC	8
ES44C4	8?
SD70MAC	8
SD70ACe	8

HP per Ton

Southern Transcon, East

On the Southern Transcon, trains east of Clovis, NM should be regulated to (i.e. must not exceed) the following maximum HP/Ton limits:

Train Symbol	HP/T
Z, section numbers 7-9	3.0
Z, section numbers 1-6	2.5
Q, S, H, or M	2.0

On most sections of line, these limits are very generous, and trains can run at much lower HP/T ratings - although high priority Z trains do often run at or near these limits.

Additional units are routinely carried UIT on westbound trains in preparation for steeper grades west of Clovis, or having been set UIT after passing Clovis eastbound.

Southern Transcon, West

West of Clovis, trains must meet a minimum of 1.4 HP per Ton.

Cajon Pass

Trains proceeding over Cajon Pass must meet the following restrictions:

Train Description	HP/T Cajon Westbound	HP/T Cajon Eastbound	Tons Cajon Westbound	Tons Cajon Eastbound
DP Intermodal	1.8	2.3
DP Coal	1.8	2.3
DP Other	1.8	2.3
Intermodal	2.0	2.5	11,500	8,500
Coal	2.0	2.5	11,500	8,500
Other	2.0	2.5	8,500	6,500

CN

HP per Ton

CN appears to target 1.0 HP/T for intermodal trains to/from Western Canada - note that CN has a very lightly graded route to both Vancouver and Prince Rupert, in contrast to other transcontinental routes.

CSX

Train Length and Weight

Network-wide restrictions for train length and weight are as follows:

Non-DPU

Attribute	Intermodal	Manifest	Bulk	Automotive
Length (ft)	12,000	10,000	10,000	10,000
Weight (tons)	14,000	14,000	18,000	10,000

DPU

Attribute	Intermodal	Manifest	Bulk	Automotive
Length (ft)	14,000	12,000	12,000	14,000
Weight (tons)	16,000	20,000	24,000	14,000

DP units must be no further than 7,000 feet from the head end of the train.

These limits may be further reduced on a local basis by siding infrastructure or other local restrictions, and may be exceeded by specially designated trains or with special approval.

NS

Length

DPU consists must not be separated by more than 8,500 ft.

In manifest trains, 50-75% of the train's tonnage must be ahead of mid-train DP consists. This limitation does not apply to trains received in interchange.

When ambient temperatures drop below 34F, a maximum train length if 10,000ft is recommended; further length reductions are recommended, down to 4,000ft below -16F. When a train has DP consists, this recommended length restriction applies to the maximum distance between any car and the nearest DP consist.

Locomotives

Trains are limited in power by equivalent conventional powered axles (EPA) as listed below (as of 2019). DC high-adhesion axles count as 1 1/3 conventional powered axles each, and AC powered axles count as 1 1/2 conventional powered axles each

Description	Head end EPA	Mid train EPA	Rear end EPA
Standard	27	18	18
Loaded Coal	32	18	18, 24 where authorised
Loaded Bulk up to 100 cars	32	18	18, 24 where authorised
Loaded Bulk over 100 cars	27	18	18, 24 where authorised

Lead and DP consists must not differ by more than one locomotive - i.e. 3 locomotives leading and 1 DP locomotive is not permitted.

Equivalent Powered Axle listing

Locomotive	EPA
All SW/GP units not otherwise listed	4
GP33ECO	5.33
GP59 / GP59E	5.33
GP60	5.33
SD60/SD60I/SD60M/SD60E	8
All SD units not otherwise listed	6
SD60E	8
SD70 / SD70M / SD70M-2	8
SD75M	8
C40-8	8
C40-9W	8
AC44C6M	9
ES44DC	8
ES44AC	9
ET44AC	9
SD70ACe	9
SD70ACe-T4	9
SD70ACu	9
SD80MAC	9

UP

Length

East

Restrictions for train makeup east of Picacho AZ, Cheyenne WY, and Denver CO are as follows:

Description	Length (ft)	Distance (ft) between DP consists
Non-DPU	10,000
One DPU consist, Intermodal	15,000	10,000
One DPU consist, other	15,000	10,000
Multiple DPU consists	18,000 (15,000 if no rear DPU)	6,000
Autorack	10,000

Trains exceeding 60 loaded autoracks must place all autoracks at the rear of the train. Trains exceeding 80 loaded autoracks cannot contain more than 5 non-autorack cars.

West

Restrictions for train makeup west of Picacho AZ, Cheyenne WY, and Denver CO are as follows:

Description	Length (ft)	Distance (ft) between DP consists
Non-DPU	10,000
One DPU consist, Intermodal	15,000	10,000
One DPU consist, other	15,000	8,500
Multiple DPU consists	18,000 (15,000 if no rear DPU)	6,000 between each consist
Autorack	10,000

Trains containing 60 or more autoracks are limited to 80 cars.

West

West of North Platte, Denver, and El Paso, the following trailing tonnage/car placement restrictions apply:

Empty intermodal cars cannot have more than 4,500 tons of weight behind them in the train.

Loaded spine cars cannot have more than 5,500 tons of weight behind them in the train.

Locomotives

Trains are limited in power by equivalent powered axles (EPA). Where multiple mid-train DPU consists exist, each is limited separately. A table of EPA ratings is given underneath the EPA limits table, along with an approximate conversion for six-axle AC locomotives (AC4400CW, ES44AC, ES44AH, SD70MAC, SD70ACe, SD70AH, etc.) in the table itself.

Description	Head end EPA	Mid train EPA	Rear end EPA	Head end AC locomotives	Mid train AC locomotives	Rear end AC locomotives
Intermodal	62	48	24	5	4	2
Manifest	52 (36 if grade exceeds 1.9%)	48	24	4 (3)	4	2
Empty Bulk	52 (36 if grade exceeds 1.9%)	36	24	4 (3)	3	2
Loaded Bulk	52 (36 if grade exceeds 1.9%)	55	28	4 (3)	4	2

Local Restrictions

All trains processing over Cajon Pass are limited to 36 EPA.

Equivalent Powered Axle listing

Note that non-UP-owned ES44AC and ES44AH units may not be capable of CTE mode.

Locomotive	EPA	EPA, 5/6 traction motors	EPA, 4/6 traction motors	EPA, 3/6 traction motors	EPA, remote consist in CTE mode	EPA, remote CTE, 5/6 traction motors	EPA, remote CTE, 4/6 traction motors	EPA, remote CTE, 3/6 traction motors
C40-8, C40-8W	7.8
C41-8, C41-8W	10.1
C44-9, C44-9W	11.5
ES40DC	10.1
ES44DC	11.5
SW1500	3.7
MP15	4.0
GP9	4.0
GP15-1	3.9
GP22	5.1
GP38-2	4.5
GP39-2	4.5
GP40-2	5.0
GP50	6.5
GP60	8.0
SD38-2	5.4
SD40-2, SD40N, SD30Eco	7.1
SD45	7.0
SD50	9.2
SD59MX	7.1
SD60, SD60M	9.9
SD70, SD70M	10.4
SD75	10.3
C44AC, C44/60AC, C44ACCCA, C6044AC	12.1	11.0	8.0	6.0
C44ACCTE, C45ACCTE, C45AH, C44ACM, ES44AC, ES44AH	12.1				11.0	11.0	8.0	6.0
CW60AC	12.1	12.0	11.0	8.0
SD70MAC	10.4			6.0
SD70ACe, SD70AH	12.0			7.0	11.0
SD70AH-T4	12.0	12.0	12.0	9.0	11.0
SD9043AC	11.6			7.0

HP per Ton

UP expresses train limits as TPA, or Tons per Powered Axle. These can be approximately translated to HP/Ton limits - the numbers below assume AC units at 4400 HP and 12.1 EPA.

Location	Minimum TPA	Minimum HP/T
Cascade Subdivision (Eugene OR - Klamath Falls OR)	170	2.1 (summer), 2.4 (winter)
Donner Pass, west slope	165	2.2
Tehachapi Pass, west slope	188	1.9

Trains over Cajon Pass must meet BNSF HP/T minimums.