TTX Car Classification Systems

Present TTX Car Classification System

The following car classification was adopted in 1968 and took until 1974 to be completely adopted. It consists of six characters.

Character:	1	2	3	4	5	6
Example:	T	W	G	5	0	P

Interpretation (partial listing)
Character:	Meaning:	Examples:
1	Car Builder	A = American Car & Foundry (ACF) B = Bethlehem Steel C = Pacific Car & Foundry D = Difco F = FMC Marine & Rail G = Gunderson, Greenbrier J = Johnstown America and Freight Car America N = National Steel Car P = Pullman-Standard R = Trinity Industries T = Thrall Manufacturing U = United American Car W = Berwick Forge & Fabricating Y = Hyundai
2	Deck Height	D = Depressed-center flatcar L = Low level (less than 39 inches) S = Standard level (39 inches or higher)
2	Other	A = All-purpose M = Integrated Multi-level car and superstructure R = Auto rack superstructure T = RoadRailer bogie W = Double-stack well car
3	Draft Gear	F = M901 or M901E friction draft gear G = M901G high-capacity friction draft gear H = Hydraulic end-of-car cushioning
3	Other	A = All-purpose B = Bi-level rack or multi-level car T = Tri-level rack or multi-level car U = Uni-level rack or multi-level car
4, 5	Design No.	For 89-foot Standard-Level Flatcars: 10 to 19 = Cars with draft pockets for friction draft gear or specific hydraulic cushioning unit 20 & up = Cars with universal draft pockets 80 = Cars with 39-1/2-inch high deck and wider side sills 90 = Older flush-deck car converted to all-purpose with universal draft pockets
		For 89-foot Low-Level Flatcars: 10 to 19 = Flatcar 60-feet over end sills 20 & up = Flush-deck car body with universal draft pockets
		For 60- to 73-foot Standard-Level Flatcars: 60 to 62 = Flatcar 60-feet over end sills 64 = Center beam car 64-feet over end sills and 60-foot inside length 71 to 73 = Flatcar 68-feet over end sills with or without end bulkheads 74 = 73-feet inside length center beam car with plate web center beam structure 75 = 73-feet inside length center beam car with diagonal truss center beam structure and 263,000-pounds gross rail load 76 = 73-feet inside length center beam car with diagonal truss center beam structure and 286,000-pounds gross rail load
		For Heavy-Duty Flatcars: Design number = Usable length of loading deck
		For Multi-level Cars and Auto Rack Superstructures: One-digit numbers = Auto rack superstructures Two-digit numbers = Complete multi-level cars
		For Multiple-Unit Cars: 2n = Two-unit cars 3n = Three-unit cars 4n = Four-unit cars 5n = Five-unit cars Second digit may or may not have a specific meaning
		For Articulated Double-Stack Cars: 50 = Cars with 100-ton articulated trucks 51 = Prototype cars built with 100-ton articulated trucks and converted to 125-ton trucks 52 = Cars with 125-ton articulated trucks 53 = (23) 100-ton cars acquired used from APL 53 = Cars with 125-ton trucks and having 53-foot wells
		For All-Purpose Spine Cars: 30 = Three-unit 57-foot TTRX car 33 = Three-unit 53-foot TTAX car 53 = Five-unit 53-foot TTAX car 55 = Five-unit 48-foot TTAX car
6	Subclass, if any	A = All-purpose C = Equipped for COFC service M = Modified from originak construction of car P = Protoype car

Original Trailer Train Classification System

Cars were assigned classes based on the length of the loading deck.

Character:	1	2	3	4	5	6
Example:	F	8	9	C	H	W

Interpretation (partial listing)
Character:	Meaning:	Examples:
1	Type of Car	F = Flatcar G = TOFC car built by GATX
2, 3	Length	Length in feet
4	Subclass, if any
6	Various	F = Equipped for auto frame service M = Modified from original construction of car P = Equipped to carry pipe W = Underframe widened for Wide-body auto rack