Thursday, April 13, 2023

Testing VIA's HEP Fleet - The Results Are In!

VIA Rail Canada (VIA) added buffer cars to both ends of Head-End Power (HEP) consists back in mid-October, 2022. Little if any information was provided by VIA at the time on the implementation of the unoccupied buffer cars, but rail enthusiasts immediately noted their presence. This led to speculation in the rail enthusiast community and even the national media. Fare-paying VIA passengers were instantly affected as baggage car access was denied and the bullet lounge view from Park cars was obscured by a trailing sleeper, leading some passengers to jokingly rename them 'bummer cars'. Many other passengers were oblivious to this implementation, ostensibly made to enhance their safety while riding the decades-old stainless-steel equipment. VIA operates 203 cars in its HEP fleet, built by the Budd Company between 1947 and 1955, so the implementation affected multiple routes and raised concerns about the fleet's future and eventual replacement.


Trackside Treasure has tracked (pun intended) the buffer car implementation since the additional cars were first observed. You'll find posts tracking the buffer cars over the past six months, the secretive testing performed for VIA, the initial HATCH engineering report, national media and trade press articles trying to get to the bottom of what was occurring, and my retrospective post showing daily changes to the  Corridor HEP consists. From what I've seen, Trackside Treasure has hosted the most comprehensive coverage of buffer cars.

Why? I have to ask myself why this has become such a pursuit for me, besides my obvious interest in daily VIA operations as a VIAphile. The answer is - secrecy. It's been frustrating to see interested parties try to divine 'the answers' while others fan the flames with speculation. In the course of this implementation, several 'sources familiar' and silent partners, some from within VIA itself, have shared information. Rail enthusiasts, consist-takers and videographers have posted consists, photos and observations. All the while, VIA has remained silent for all intents and purposes, or so it seems. For example, the cars for compression testing were sent to Ottawa at night, stripped and wrapped, apparently to make visual identification impossible.

After the issuance of the Transport Canada ministerial order, and the passage of the reporting dates set out by the order, it has only been through Access to Information (ATI) requests that I have been able to personally obtain definitive data from VIA. 

This is disappointing to me. I'm a taxpayer, and you are likely one, too. We're all potential VIA passengers. Many of us have VIA trains passing through our communities, sharing tracks with freight and other trains. We are owed some sort of accountability, if not transparency. Imagine the outcry if similar deficiencies were found in the national airline fleet and kept quiet by the air carriers, or detected by auto manufacturers without recall notices being issued! Fortunately, there is recourse for individuals in the face of this silence, and it's thanks to existing access-to-information legislation.


In response to the aforementioned ATI requests, VIA fulfilled its responsibilities under its own Governance & Ethics policies. I have found their responses professional and responsive. No restrictions were placed on sharing this information by VIA.

I'm a railfan, not a professional engineer, or even a locomotive engineer! I'm interested in car names and numbers, the future of VIA's fleet that I can observe and photograph, and more generally, safe and reliable rail transportation within Canada. The reports provided to me are engineering reports, and more complex than I'm used to dealing with. So I'm not able to divine details from graphs nor parrot a lot of engineering terminology that I'll either have to define, or that you need to Google! Elements from the reports are contained in the following sections. Let's get to the results!


Based on the six paragraphs of the order, these were the requirements for mitigation, testing and reports submitted to the Senior Manager of Engineering at VIA, and the effective dates of each:
  • 1 - Implement buffer cars (October 19, 2022)
  • 2 - Engineering simulation of predicted HEP car collision performance (October 31, 2022)
  • 3 - Tear-down inspection of four HEP cars with structural defects (January 31, 2023)
  • 4 - Static structural test of two unrepaired HEP cars (January 31, 2023)
  • 5 - Final report incorporating 2, 3, 4 (March 31, 2023)
  • 6 - Static structural test of one repaired HEP car (December 31, 2023)

To assess the effectiveness of buffer cars, an engineering analysis was conducted to simulate various train-to-train collision scenarios. The purpose of the analysis is to confirm that the unoccupied buffer cars reduce the consequences of a collision event in the adjacent occupied cars. The engineering analysis includes one-dimensional train-to-train crash scenarios with a standard FRA reference train of one locomotive and five coaches. The subject train of the analysis was VIA’s revenue-service HEP fleet trainset with different consist sizes to simulate different services, such as the Corridor (one 900-series locomotive and five coaches), Skeena (one 6400-series locomotive and three coaches), and Canadian (two 6400-series locomotives and 21 coaches).

The analysis was intended to demonstrate how collision energy was dissipated along various train configurations with buffer cars. The analysis would not predict the actual outcome or all possible behaviours of the train in a collision event. The simulation was consistent with industry practice for demonstrating low and medium speed collisions with limited crush. 

VIA's HEP fleet of Budd-built cars are constructed of a stainless-steel body, frame, center sill, side sills and cross bearer beam, in combination with carbon steel draft sills and body bolsters using rivets or plug welding to connect the sections of dissimilar materials.

Engineering analysis found that a Lead Coach Vehicle Body Front End Crush impact (the crush zone of the first coach behind a locomotive) could extend up to 100 inches, the limit for the fidelity of a coach's end crush zone. This was of course estimated, prior to the actual compression testing of an unrepaired HEP car, completed soon after by the National Research Council in Ottawa.

Based on the Transportation Safety Board Rail Occurrence Database System (RODS) information on a sample of Head-on/Rear-end collisions, 50 out of 68 collisions with speed more than 15 mph resulted in derailment (74%) and 15 of the 18 non-derailed trains had fewer than 20 cars. In collisions with speed more than 20 mph, 29 out of 36 collisions  resulted in derailment (81%) with 6 out of the 7 non-derailed trains having fewer than 3 cars.

Most rail enthusiasts decried buffer cars as not effective in stopping a 15,000-ton potash train going 50 miles per hour, or some other fairly wild estimate of the David-and-Goliath crash scenario of a CN versus VIA train. The above criteria detail makes it clear that such an extreme collision was never the scenario envisioned prior to the analysis, and was also not envisioned for the protective value of buffer car implementation. VIA informed Hatch verbally that in the last 30+ years there had been no accidents that resulted in actual carbody longitudinal deformation. Many buffer-car doubters pointed to the August 17, 1959 Gull Lake, SK collision between a CP train Nos 8 and 6, and the 69 resulting injuries as the most recent such scenario example of a serious train collision. However, the 30+ year timeline just misses the February 3, 1986 date of the catastrophic Hinton, AB collision and derailment involving CN No 413 and VIA No 4/6! Ideally, lessons learned combined with improved technology will, and have, lead to further reductions in the possibility of such collisions occurring.

As a result of the analysis, the temporary mitigation plan to use an unoccupied buffer car behind the leading locomotive and as the end coach of the consist, was supported by one-dimensional analysis results, and would reduce the consequences of a collision event.



The required teardown inspections on four HEP cars, VIA 4006 (HEP2 Business), 8225 (HEP1 Chateau Rouville), 6208 (RDC-2), and 8402/Alexandra (Diner) were completed on January 20, 2023.  Gerry Burridge kindly shared a photo (top) of the latter two cars taken outside CAD on February 12, 2023 looking torn-down! These cars were selected as representatives of the age, the various structural configurations, and general condition of the entire HEP fleet. The tear-down inspections were planned in detail and completed in three primary phases: 
  • i) a complete strip-down of each car,
  • ii) accessing by cutting and cleaning inspection visually inaccessible areas, and
  • iii) detailed inspections.
The goal of inspection was to assess the presence of already known structural conditions using NDT (Non-Destructive Testing such as dye penetrant) or other means, and to identify additional structural conditions visible only by invasive type inspection. VIA hired Hatch to prepare the strip-down and tear-down procedures, perform the inspections including data collection, provide recommendations and prepare the reports. The inspections were conducted at the CAD Railway Industries shops in Lachine, QC, a qualified industry contractor, as supervised by VIA and Hatch staff.

The inspected cars required full interior and underframe strip-down to access structural elements and their connections. Once strip-down was completed, the cars were cleaned to remove materials obstructing inspection of the car shell such as insulation, paint, primer, shimming, adhesive residue, corrosion product, and dirt. The tear-down phase involved the cutting of certain structures.

All four cars were inspected visually (VT), as well as with a liquid penetrant crack indicator (PT) and using ultrasonic measurement (UT) to assess the thickness of parts. These methods were applied to primary structural elements and their connections, as appropriate, following the inspection procedure.

Data from the inspections was compared to the VIA’s previous STR Inspection condition data collected from other vehicles in the HEP fleet. Five of the eight known conditions were found among the inspected cars. Condition 5 and 6 (visible crack on the transition zone) was not found and Condition 7 (Dome Car cross bearer damages) is not applicable to the 4 cars inspected. 

The tear-down revealed five conditions not seen during VIA's normal visual inspections:

1. Bolster to Side Sill Connection: Plates associated with the bolster connection at the side sill exhibit substantial corrosion deterioration that can only be quantified with the removal of other structural elements. This was found on all four cars. In some cases, holes due to corrosion were found in the structure adjacent to the connection. VIA applies repairs at such locations based on presence of cracked connection plug welds. 

2. Bolster to Side Sill Top Plate Interior Connection: Partially cracked welds were identified on one car only, car RDC-2 6208, in a gusset connecting the top plate of the bolster to a post; separation or detachment were not observed. Partly corroded welds were also found on 8225, 4006 and 8402, where plate thickness loss was also observed. These defects are not visible without the removal of significant interior components. The RDC car has a different design than the other HEP cars and may need to be assessed differently.

3. Significant thickness loss was noted on tops and sides of body bolsters of car diner 8402, under the kitchen area, and 6208 and 4006 at dissimilar metal interfaces. This observation was made by the removal of floor structure and using a pattern of UT measurements. Some UT measurements are currently made during VIA’s routine inspections from the underside on exposed areas, but not to the same extent performed during the tear-down inspections, due to access constraints. 

4. Center Sill Transition Zone Plug Welds (where present): On two cars out of the four inspected (8205 [sic] and 8402 - the two other cars have different connections), partial cracking around the circumference of the plug welds was observed on the inside surfaces, seen when floor pans are removed, but same was not visible on exterior side. Complete separation of the connections was not observed. VIA’s standard repairs would address this condition.

5. Areas of the carbon steel structure fully exposed to the environment exhibited very low corrosion loss. Stainless steel members did not show signs of thickness loss or degradation. This suggests that inspection efforts can be focused on crevices, overlapping parts and dissimilar metal areas.

6. Collision posts: The carbon steel internal members of the collision posts were accessed for inspection as part of the tear-down procedures. Non-significant deterioration was observed on any [sic] of the posts. Stainless steel portions of the post did not show any deterioration. 

The tear-down inspections conducted on the four cars suggest that VIA’s inspections can capture all the visual defects conditions. However, such inspections are not providing the data needed to evaluate the non-visible conditions of the cars, notably at dissimilar metal interfaces that trap corrosion accelerators. Therefore, the tear-down inspection of additional cars, to be completed by March, may help to extrapolate these conditions on all cars. 

In addition, the tear-down inspections may demonstrate the need for different inspection procedures and any repairs required at the bolster and its connections, if this is deemed a critical structural integrity concern. VIA’s HEP fleet is comprised of multiple car configurations, and different design vintages within a given car type, hence the approach must consider these variants. The implications of this finding on VIA's HEP fleet are manifold, and not all configuration variations have been examined yet. Therefore, it is prudent to continue with the planned tear-down inspections.

Notably, although four torn-down cars were photographed outside CAD on February 12 (RDC, diner, Chateau, Business Class), three more cars (Manor, Skyline, baggage) representing additional car types were photographed on March 25. These likely represent the continuation of the wider VIA fleet tear-down inspections as referred to above.


A static structural test on certain unrepaired HEP cars to validate the structural capacity of the cars to the requirements of the Association of American Railroads Standard S034. The compression test load to 800 kips on the line-of-draft in accordance with OEM (Original Equipment Manufacturer) Standard AAR (Association of American Railroads) S-034:1945, was performed on two HEP cars: 8222 (Chateau Richelieu) and 8138 (Coach 'SEPTA') on December 15, 2022, and January 19, 2023 respectively. 

Pre-test inspections were carried out on both cars showing that they are representative of general degradation in the fleet. Chateau Richelieu/8222  had general corrosion and material loss mainly on carbon steel surfaces at Draft-Sill top surface and cracks and defects on Side-Sills. Coach 8138 had general degradation and corrosion at Draft-Sill and Center-Sill/Draft-Sill A-End Transition Zone, as well an unrepaired Condition #5 defect on A-End LHS.

The test cars were fitted with strain gauges in five cross-sections: three mid-sections at the stainless-steel portion and two end-sections at the end-underframe assemblies with carbon steel construction. The strain gauges were attached to the structural members on the longitudinal load path to evaluate the criteria of the AAR standard of 800 kips - kips are customary US measuring units of force where one kip equals 1000 pounds-force - compression on the line-of-draft load case for (a) maximum allowable strain at maximum load application, and (b) residual strain and permanent deformation after load removal. 

Both cars successfully passed the structural criteria of the tests, based on three pass/fail criteria:
  • There were no visible cracks, fractures, separations or permanent deformation within the vehicle structure.
  • Strain gauge readings showed no stress values exceeding allowable yield strength of structural members.
  • Residual strain readings are below defined criteria after removal of maximum load, confirming no permanent deformation.
The compression test was continued to the ultimate load capacity of Chateau Richelieu above the required 800 kips load. Coach 8138 was tested to 800 kips to this date, as it was decided to postpone the ultimate test for other interim testing. After performing the envisioned internal tests, 8138 will be tested to ultimate sometime in February 2023.

The testing on Chateau Richelieu carbody showed fully elastic behaviour to ~885 kips of applied load, which gives approximately 10% safety margin against the required 800 kips compression on the line-of-draft load case. The global buckling of the carbody shell occurred at 1,045 kips of applied load. This load is identified as the ultimate load capacity of the car.

Further details of the analysis of test outcomes, including further testing of 8138 and compression testing of a Park car, will be reported at a later stage on or about March 31, 2023.


Conclusions released increase the extent and locations checked by UT measurements on focus areas such as crevices, overlapping parts and dissimilar metal areas when performing a repair and on scheduled car inspections. The car preparation process should be modified to include abrasive cleaning of areas that facilitates UT measurements. The impact of degraded Bolster to Side Sill Connections on the integrity of the car should be investigated and the current repair should be revisited, as necessary.

Assumptions used in the Crash Analysis (Simulation) of the Buffer Car Operation were valid and conservative. The investigation and analysis to evaluate the necessity of operational mitigation with buffer cars is in progress using the current test results. The temporary mitigation plan using buffer car continues and will be re-evaluated once the testing program is completed.


The cost, not just the financial cost, of this testing was the reduction of VIA's HEP fleet by at least 11 cars: one-sixth of its remaining RDC fleet, one-twelfth of its diners, one-ninth of its Business Class cars, an overall five per cent of the total HEP fleet. No fewer than three of the cars sacrificed were unlikely to see service again, however, so perhaps their loss is not as dramatic as it might at first seem.

VIA, in its 2023 First Quarter Report risk analysis released in May, said, "The ... HEP rolling stock equipment has essentially reached the end of its operating life. Its reliability has deteriorated in the past few years, resulting in delays and additional operating costs to maintain a state of good repair."  Then, giving as much information on the testing as it ever has publicly, continued, " aging fleet requiring more inspections and repairs, as a result of which service revenues and costs as well as equipment availability will benegatively impacted in the future.

Following the discovery of new structural conditions with the HEP equipment, and the filing of a thorough engineering assessment by a competent third-party, the Corporation had to put in place additional safety measures to mitigate the safety concern until a structural reinforcement and repair program of the entire HEP fleet has been undertaken. These measures included the use of buffer cars, tear-downs of cars with structural defects to identify potential additional structural conditions as well as structural compression tests to validate the structural capacity of the HEP cars.

The results of these measures showed that the structure of the equipment is adequate and the structural
reinforcement and repair program will not be as substantive as initially projected. In addition, the ministerial order issued by Transport Canada in October 2022 requesting that the Corporation add buffer cars in its trains was lifted on May 18, 2023."

Once the final March 31, 2023 report provided to Transport Canada is released, I'll be publishing additional information, more testing results, conclusions and recommendations. After six months, it is good to have solid data that can be made available, albeit through an ATI request to VIA. 

Never in Trackside Treasure's nearly 15-year history has a series of posts been constantly updated over such a period of several months.

Published June, 2023 this post profiles the final report provided by Hatch Engineering to VIA thence Transport Canada.

Running extra...

Spring has sprung, the grass has riz. I wonder where the flowers iz? 
(Only in Kingston can we grow limestone-coloured grey tulips!)
It's been a long winter of wondering. Wondering when this particular VIA mystery would ever clearly revealed by our national rail passenger carrier. Wondering if Access to Information requests were ever going to be responded to. Wondering, along with many others, if the former CPR Canadian fleet's time had finally run out. 

But, patience! Like a garden bed full of tiny bulbs' breakout with fresh green shoots through the autumn's leaves, maybe if we wait just a little longer, if we let the glaring light of day bring forth the story, that it will blossom into a fulsome, truthful account of the events that began last October. Actually, much longer ago than that, because who knows when the various structural elements of these cars started showing their age!


Anonymous said...

Thank you for all of the information over the many months Eric!!! It has been greatly appreciated. At the time the Buffer Cars were added to VIA Rail trains, I was working on an extended trip to Churchill along with visits to numerous other destinations within Manitoba (4 - 6 week stay). Due to Buffer Cars, that trip was Scrapped and I’m heading to Scotland with numerous train rides already booked and working on more. I’m very interested in learning more about VIA Rail’s future plans and will check in every so often. I had hoped to ride many of VIA Rail’s long distance trains with extended stays in a number of provinces. European trains and extended visits are also an option, especially if VIA Rail Buffer Cars remain in place or service is suspended.

Eric said...

Sorry to hear that the buffer car implementation led to that cancellation, A. But glad to hear Trackside Treasure was useful in your trip planning.

Hopefully Scotland will be more straightforward and there will be no MacBuffers or anything like that!

Yes, do check back as I am expecting further elucidation on VIA's somewhat murky plans.