by James Costello

The BLMA RAF53C Model

BLMA recently released the first run of their Trinity RAF53C All Purpose 5-unit Spine Cars in N scale.  The 3-unit sets, RAF33’s, are on the horizon as well.  Let’s take a look at the BLMA model and the prototype these models represent.

Photos of the BLMA RAF53C AP Spine Car Model

Prototype Spine Car Development

Since the development of a light weight articulated spine car for Trailer On Flat Car (TOFC) use by the Santa Fe in the late 1970s, the concept has evolved into the backbone of North American intermodal TOFC transportation.

Experiments with Impaks, Fuel Foilers and articulated container-only spine cars throughout the 1980s succeeded in 1989 with the introduction of Trailer Train’s All Purpose Spine Car, a set of five articulated spines capable of carrying trailers and containers. Originally built by manufacturers Thrall, Gunderson, Trinity and Bethelehem, these cars could carry 28’ to 48’ trailers or 40’ to 48’ containers on all platforms. The end platforms could also carry two 20’ containers. The versatility of the car was such a success that the first two years of production of these spines delivered more platform capacity to Trailer Train than the previous eight years of spine car production combined, with almost 10,000 platforms delivered by 1991.

Whilst production of the 48’ All Purpose (AP) Spine continued into 1992 and 1993, the year 1993 also saw production commence on the next evolution of all purpose spines, with capacity increasing to handle the future wave of 53’ trailers and containers. Between 1993 and 1997, just over 3,600 53’ AP spine car sets were manufactured by Trinity (53%), Johnstown America (39%) and National Steel Car (8%) for TTX (renamed from Trailer Train in 1991). That represents another 18,000 intermodal platforms in just four years. The October 1998 edition of Model Railroading magazine features a photo intensive article by Doug Geiger that identifies some of the spotting features between the various builders of the 48’ and 53’ AP Spines. A link to the Trainlife hosted magazine article is provided in the references.

Beginning in 2004, to match the decline in 48’ trailer traffic and the increases in 53’ equipment, TTX began rebuiling sets of the Trinity built 48’ AP spine cars to handle 53’ trailers.  These rebuilt cars feature a very distinctive wheel tray at the extension (TTAX 555500 – 556999), as well as an extension of the A and B platforms of the cars.  The original scope of the program was to encompass 1,500 spine car sets, but due to the cost of the required modifications, as well as the reduction of TOFC volumes during the financial downturn late in the program, the full extent of the program was never realized and rebuilt cars are found scattered throughout the series limits.  The majority of the un-rebuilt 48’ spine cars were repurposed into windmill blade service, were stored, or have been scrapped.

To increase the versatility of these cars for railroads and in a sign of things to come, Trinity manufactured 200 three-car sets of the 53’ platform for TTX at the end of 1997. The final stage of evolution began in 1998 when Trinity demonstrated a new all 57’ purpose spine car set at the 1998 Intermodal Expo. These three-car sets feature a longer spine and wheel tray and an additional hitch at the rear of the spine to cater to the movement of two 28’ trailers placed back to back, dramatically increasing the railroads efficiency in transporting Less-Than-Load (LTL) trucker’s trailers. Due to the longer length of the unit, a single trailer up to 57’ in length can also be transported, though 57’ trailers are not typically seen moving TOFC, and only limited use on the highways.

The Trinity-built 53’ft AP Spine Cars

A full roster of the all purpose spine cars is provided at the Intermodal Archive web site with the TTX Trinity built cars summarised in the following table:

TTX Trinity 53’ft All Purpose 5 Car Sets

Number Series
TTAX 553000-554159 (1160)
TTAX 554160-554659 (500)
TTAX 555000-555239 (240)
TTAX 555500-556999
…. TTX Class
RAF53 / RAF53A
…. Comment
8/1994, 1-6/1995, 9/1995
48′ rebuilt to 53′ platform

TTX Trinity 53’ft All Purpose 3 Car Sets

Number Series
TTAX 355000-355199 (200)
…. TTX Class
…. Comment

Spines, like other articulated and multi-unit cars, have their end units designated A and B and their intermediate units to suit. A 5 car set has units designated A-E-D-C-B and a 3 car set is A-C-B, and are equipped with hand brake wheels at each end unit. 
All TTX classes of the Trinity built five car and three car sets feature the same basic body structure. The RAF53, RAF53A and RAF53B classes all feature container mounting pedestals that enable loading of two 20’ containers on the end units (Units A and B). These pedestals flip up from within the deck of the wheel tray when they are required. When they are not required, the pedestals are hidden by a cover plate.

The main difference and spotting feature between these classes and the later RAF53C / RAF33 classes is that these sets both lack these pedestals and the ability to carry 20’ containers on the end platforms. A thin raised area is visible in the deck where the void for the pedestal would be in these cars.

The following photo demonstrates the difference between the RAF53C and the earlier classes such as the RAF53A. Note the insert that shows the cover plates flipped to open to the container pedestals.

Back-dating a model of the RAF53C to represent the earlier classes would be possible with an etched metal cover plate to represent the closed pedestal covers. The same detail part, with some fabricated pedestals, could also represent a platform loaded with 20’ containers.

Understanding Trailer Train AP Spine Car Classes

1st Digit = Builder
R = Trinity
J = Johnstown
T = Thrall
B = Bethelehem
G = Gunderson
2nd and 3rd Digit
A = All Purpose
F = Flat Car
4th Digit = # of Units
5 = 5 unit car
3 = 3 unit car
5th Digit = Spine Length
5 = 48’ Spine
3 = 53’ Spine
0 = 57’ Spine
6th Digit(if req’d) = Phase
Example A,B,C
Example – RAF53C = Trinity built, All Purpose, Flatcar, 5-unit, 53′ Spines, Phase C.


All Trinity 53’ AP spines feature Trinity LP12-42 trailer hitches – their LP12 hitch built with a 42 inch high top plate. The top plate of the hitch has two lifting loops welded to each side of the plate to enable lift equipment to raise the hitch from a retracted position. A hitch is lowered manually to facilitate trailer loading. As the hitch slides backwards as it is retracted, the LP12 was designed with a cover plate to prevent access to this area by terminal staff. However these cover plates were a high maintenance item for TTX as they were easily damaged during the loading process and bent out of shape. In the summer of 2000, TTX began replacing the cover plates with barriers made from small steel angle mounted to the center sill. These barriers prominently display warnings to staff to keep clear of this dangerous area of the hitch.

A pre-2000 model of the LP12-42 could be made by removing the barriers and representing the cover plate with either an etched metal detail or styrene. MLE Scale Models also produces replacement hitches for spine cars in both N and HO scales.

Part 5 of Jim Panza’s excellent series of trailer hitch type articles features Trinity’s all purpose spine car hitches in the July 2002 edition of Railmodel Journal magazine.

Photos of Trinity RAF53C All Purpose Spine Cars (Chad Hewitt Photos)

Photos of Trinity RAF33 All Purpose Spine Cars (Chad Hewitt Photos)

Reference: Trinity Spine Brochure


The author would like to acknowledge the assistance of Chad Hewitt for the information and photographs supplied and to the modelintermodal Yahoo Group members for their efforts in documenting and discussing intermodal transportation equipment and operations.


Panza, Jim “Trailer Train’s TTAX All Purpose Spine Cars” Railroad Model Craftsman Magazine, Carstens Publications, October 1991, Page 62.

Hewitt, Chad – Message #25251 at modelintermodal Yahoo Group, 21st October 2009 (group members only)

Hewitt, Chad – Message #26476 at modelintermodal Yahoo Group, 29th November 2010 (group members only)

Panza, Jim “Trailer Hitches, Part 5: Modelling the Trinity Industries All-Purpose Spine Car Hitches” Railmodel Journal Magazine, Golden Bell Press, July 2002, Page 11

Intermodal Archive website –

All Purpose Spine Car Roster –

Wilson, Jeff The Model Railroader’s Guide to Intermodal Equipment and Operations, Kalmbach Books, 1998

Geiger, Doug “Spine Cars – Part 3: All Purpose” Model Railroading Magazine, Highlands Station, October 1998, Page 34

MLE Scale Models website –

Casdorph, David “Intermodal Modeler’s Heaven – A Report From The 1998 Intermodal Expo” Model Railroading Magazine, Highlands Station, September 1998, Page 30