Difference between revisions of "Train Makeup"

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On most sections of line, these limits are very generous, and trains can run at much lower HP/T ratings.
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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 may be placed UIT on the train in preparation for steeper grades west of Clovis.
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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 ====
 
==== Southern Transcon, West ====

Revision as of 10:09, 15 April 2022

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.

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.

Weight

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

Horsepower per Ton

UP expresses train limits as TPA, or Tons per Powered Axle. These can be approximately translated to HP/Ton limits.

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.