Yesterday, VIA was informed by CN that there may be safety issues with Siemens Venture trains not shunting properly. This post will explain why I've used the term Buffer Car in the post title.
LET'S TALK ABOUT SHUNT
Shunt is basically the act of a locomotive and or rail car completing (shunting) the circuit in a section of signaled track to show occupancy. Signal systems are divided more or less into blocks or varying lengths, depending on the territory. When there is no train in a block, the block will show as "clear". When a train enters the block, the wheels and axles bridge the "gap" between the 2 rails, completing the circuit and showing that the block is occupied. The act of the wheels and axles completing the circuit is called shunting.
Why is this important? Well, if a train loses shunt or shunts intermittently, that can create lots of problems for the signaling system! Lineside signals, crossing protection, every warning device relies on block occupancy and shunt to function properly. Passenger equipment is, on average, much lighter than freight equipment, and can lose shunt more easily. This is why railroads like CN and CSX have imposed minimum axle counts in passenger trains (usually 20 axles or more), because they were having issues with passenger trains failing to shunt signals and or crossing protection. This is also the reason why railroads usually limit single light engine moves to 30 mph or less, as a single locomotive moving faster than that can run the risk of losing shunt. This has happened with single locomotives running light in an approach-lit signal block. The locomotive lost shunt and the signal actually shut off for a few seconds before flicking back on!
Why is CN stipulating 32 axles as a minimum for Venture trains on its lines? What is the right train length based on testing? At some point, longer is better: as each wheel passes over a piece of rail, the contact area on the rail gets increasingly cleaner. A lesser number of wheels cannot provide enough cleaning. This is complicated by the absence of tread brakes on Ventures. Wheels cannot get completely clean; nothing is there to scrub the wheels' face. And because the contact patch of the wheel is variable in lateral movement, they never get clean enough to ensure proper continuity.
This appears to be a problem that only CN is experiencing, largely due to the design of its signal system. Other railways' signal system designs don't suffer from the same drawbacks. CN requires a minimum of 12 axles for track-speed operation of a movement. That explains this odd assemblage I observed back in June - the shortest freight train ever! Actually a deadhead movement of a spare locomotive to assist a freight train, and a freight car plucked out of Belleville yard and tacked on the tail-end got it there faster, at "close to track speed"!
VIA ISSUES ITS FIRST SYSTEM NOTICE
On October 11, 2024 VIA released the following document, which references a CN document entitled 'Venture Equipment Crossing Supplement' which is available to CN employees operating on the Great Lakes and Champlain Districts, under CN Timetables and Special Instructions. Here is the text of the VIA document:
System Notice No. VN24-022 dated October 11, 2024
VENTURE EQUIPMENT - RULE 103.1(f) ON CN TERRITORY
Our host railway, CN has issued restrictions on our Venture fleet related to a potential risk of short warning times on crossings equipped with Grade Crossing Predictors (GCPs). Such crossings utilize technology to estimate your train's speed to determine a sufficient warning time for vehicular or pedestrian traffic. While we continue to work with all stakeholders to resolve this issue as soon as possible, we must convey these restrictions.
The first priority, as always, is the safety of your train. We understand these conditions will introduce additional distractions and competing priorities. We must ensure we remain focused at all times to comply with these restrictions. VIA understands and anticipates that significant delays may be experienced and wants to reaffirm our expectation that our crews will take their time to ensure no restrictions are missed.
CROR Rule 103.1(f): When advised by special instructions that rusty rail or other conditions may exist, occupancy of crossings with automatic warning devices must be manually protected unless it its known that warning devices have been operating for at least 20 seconds.
The VIA Venture Equipment Crossing Supplement can be found [online]. We are also working to provide paper copies of this document at all reporting locations. [Additional bullet points below]
- All trains in possession of a General Bulletin Order instructing you to comply with the Venture Equipment Crossing Supplement must comply with these restrictions at all specified crossing locations.
- At this time, the restriction only applies to Venture trainsets with less than 32 axles. Mixed consists and those consisting exclusively of Legacy equipment (LRC/HEP/Renaissance) equipment are not affected.
- We can't just add more Venture cars. Due to existing reservations and planning constraints, we are limited in our ability to extend trains on short notice. That said, we are doing all we can to minimize impact through all available means.
- The document refers to a shunt enhancer. VIA is actively engaging with suppliers to evaluate and procure these devices. New technology is under development and becoming available to mitigate these risks. At this time, however, we can confirm that no VIA Rail Venture trains are equipped with shunt enhancers.
- These restrictions were not communicated to VIA in advance, and we continue to exhaust all avenues to resolve this issue as quickly as possible. VIA's commitment to safety remains steadfast and we will work with all stakeholders to address any safety concerns.
VIA ISSUES ITS SECOND SYSTEM NOTICE
On October 13, 2024 VIA released an additional, clarifying document.
Here is the text of the additional VIA document:
System Notice No. VN24-023 dated October 13, 2024
VENTURE EQUIPMENT - CN INFRASTRUCTURE RESTRICTIONS
Further to Friday's notice related to restrictions imposed by CN, we have been monitoring train performance to measure the impact on our services. Unfortunately, the results indicate a potential widespread misapplication/misunderstanding of the rule. Venture trains subject to these restrictions MUST approach each identified crossing prepared to stop until it can be confirmed that A[utomatic] W[arning] D[evice]s have been operating for 20 seconds. This applies to ALL crossings identified in the [CN Great Lakes/Champlain District Special Instruction] "VIA Venture Equipment Crossing Supplement" document. To be frank, this cannot be accomplished if you are operating at, or close to, maximum track speed.
In order to ensure proper and consistent application of these restrictions and until further notice, the following additional restriction is in effect and will be monitored for compliance:
In addition to the requirements of Rule 103.1(f), all affected movements governed by the VIA VENTURE EQUIPMENT CROSSING SUPPLEMENT must not exceed 45 mph from one-quarter mile of each crossing identified. Acceleration may only commence AFTER passing the one-quarter mile and after confirming AWDs have been operating for a minimum of 20 seconds.
Note: The 45 mph restriction may not provide sufficient speed restriction to permit stopping in the event of insufficient warning time at the crossing. When encountering inclement weather or extended braking distances (e.g. rail contamination such as falling leaves), a slower speed may be required.
We understand these restrictions pose a significant burden and inconvenience, but they are necessary to protect the situation. We appreciate your understanding while we work with CN and with Transport Canada to resolve this situation as quickly as possible.
CN'S "VIA VENTURE EQUIPMENT CROSSING SUPPLEMENT"
Here is the text of the CN document referred to in VIA's October 11 System Notice:
Unless operating with 32 axles or shunt enhancer, the following crossing mileages listed under each Subdivision must be manually protected unless it is known that warning devices have been operating for at least 20 seconds as per CROR 103.1 (f). Applicable on the following Subdivisions: Dundas, Chatham, Guelph, Halton, Strathroy, Kingston, York, New Market [sic], St Hyacinthe, Montreal, Drummondville.
There follows a l-o-n-g list of crossing mileages. There are 86 crossings on the CN Kingston Sub list alone, beginning at Mi.17. In this area: Counter Street, pedestrian crossing at Frontenac S.S., Collins Bay Rd., Coronation Blvd., not County Road 6 then only one other crossing between Ernestown and Napanee. So it's not every crossing, but it's A LOT of crossings. For a train routinely doing 80 mph, slowing to 45 mph or less 86 times will likely total the 30-60 minute delays VIA is telling its passengers about.
[As for monitoring crew compliance by VIA, just think....VIA managers can sit at their consoles in Montreal or at home, monitoring Venture train speed in real-time using VIA's own Arrivals & Departures website feature that displays location and speeds at one-minute intervals!]
SHUNT ISSUES ELSEWHERE - AMTRAK & CN
In mid-August, 2023 the latest instalment of an ongoing series of tests was staged out of Canadian National’s Effingham yard in southern Illinois. The sessions, attempting to seek a permanent solution for locations where loss-of-shunt issues are ongoing, were attended by participants from CN; Amtrak; the Federal Railroad Administration; the Illinois and California transportation departments, and equipment vendors.
At that time, CN said that extensive testing had indicated that the random loss-of-shunt detection events experienced by single-level passenger equipment [on CN lines] in the US was due to the absence of sufficient contact area between the wheels of passenger trains and the rail head. The wheel profile of a passenger car has a smaller contact area, which CN says contributes to loss-of-shunt. The smaller contact area on the wheel profile of passenger equipment, combined with short and light trains, prevents the systematic sufficient transmission of current necessary to activate fully operational and FRA compliant railway crossings.
In September, 2023 there were issues in the US with various Amtrak trains not properly shunting track ("loss-of-shunt") to trigger warning signals at level crossings. Addressing why Superliners were required on the Illini-Saluki route, the company asserts, “Due to the safety concerns, CN required either the use of heavier equipment or lowering the maximum operating speed at grade crossings for single-level equipment on this route. This was the responsible thing to do to ensure safe operations.” The speed restriction does not apply with Superliners, which were found to consistently shunt the circuit. Events occur where the combination of consistently trued wheel profile, lightweight equipment, and minimal axle counts are present. It is false to claim it only happens on some routes, as any route with these aspects present would likely result in random loss-of-shunt events.
John Black, a member of the Loss-of-Shunt Technical Committee, reached out to Trackside Treasure with additional information, including a link to this Federal Railroad Administration (FRA) 1993 report [spoiler - dullness warning, according to John!] The temporary loss-of-shunt (which may cause deactivation) in grade crossing warning devices, while the train spans the crossing, created a question of reliability in the minds of individuals dependent on them. For this reason, the railroad signal community asked the AAR Research and Test Department, in co-operation with the FRA, to study the loss of shunt problem. The report describes work results and recommends future direction for FRA-funded efforts, also describing AAR/Committee-funded efforts.
Going way back to the days of the RDCs, loss of shunt was a problem with both grade crossings and CTC circuits. This is where the investigations were started, but they really didn't pick up any co-ordinated effort until an Amtrak train on CN tracks in Michigan hit a vehicle and killed the occupants. There had been several documented reports of activation failures at this crossing with no apparent equipment malfuncton found. The US Federal Regulator found CN at fault, which was the start of mandated minimum-axle counts, and CN was directed to lead an industry-wide task force to find mitigations for the loss of shunt issue.
Following CN's lead, other railroads initiated minimum-axle counts for passenger trains on certain subdivisions. This has impacted regional trains, which are now mostly funded by the States, and having to lug around an empty car adds a significant cost to the operations already struggling post-pandemic.
Loss-of-shunt issue is a real concern, and it affects the lighter passenger equipment moreso than the freight equipment, or even VIA's Legacy passenger equipment.
Why? First, passenger equipment is maintained and inspected to a higher standard to that of freight equipment, especially when it comes to wheels and ride quality. Wheel profiles are maintained to a much stricter standard on passenger equipment to provide superior ride quality. In doing this, it moves the wheel to rail contact patch higher up onto the rail head, out of the normal freight wheel back and forth slog. The tops of rail are hardened, and as such are much harder to clear of contaminents, so a few short passenger trains of a lighter weight are not enough to polish the hardened rail heads, and keep them free of contaminant.
Secondly, Most of the railroads have in their special instructions, minimum axle counts for trains and engine movements, and some even have speed restrictions associated with the minimums. This is due to loss-of-shunt.
So, it is no surprise the CN has forced VIA to add axles to the Venture train sets. Even though the trainsets may be activating the circuits adequately, it is a policy CN has adopted system-wide to show they are addressing the issue until vehicle-borne shunt-enhancing systems can be deployed. [Thank you, John!]
LET'S TALK ABOUT SHUNT SOME MORE
How can this still be a problem after all the trains operating on many railroads for decades, including lightweight RDC's, Turbo trains, and other trains with single-level equipment? I suspect the lawyers were involved and crossing gates must work 100% of the time. If I'm driving over a level crossing, even 99% is not good enough. Who can forget VIA's operational challenges during the ADtranz Flexliner demonstration period in 1996-97? There were early technical problems - signals not being activated due to the cars' light weight, which led to a Transport Canada-mandated withdrawal from service on September 30. Flexliner trainsets could apparently 'disappear' from dispatcher's computer monitors! The units were stored until further testing took place in early October. Composite brake shoes were replaced by steel brake shoes.
There are various technologies mentioned online but I'm not enough of a S&C expert to say which ones work, are likely to be implemented or apply to this current situation. But that's not going to stop me from wondering what we're likely to see trackside, and whether this will indeed be Buffer Car 2.0! I have a lot to learn. Trainorders site provided excellent information on the evolution of three different technologies involved in crossing circuits:
Old-style AC/DC crossing circuits with insulated joints that acted as an on/off switch. The train hit the circuit and turned on the protection. It was fixed and had simple relays. The insulated joints were marked out to the distance of the fastest moving train speed which set the minimum warning time of about 30 seconds. So an 80 mph passenger train would have a 30 second warning and a slow crawling freight would have a far longer gate down or flasher on time, which many times encouraged motorists to go around the gates or run the crossing. Very hazardous situation.
Sensors are electronic circuitry that are more advanced than the AC/DC, and sense a train when it hits the circuit controlled by shunts.
Predictors evolved in order to take into account varying train speeds and keeping gate and flasher times consistent so that an 80 mph train and a 20 mph train will have the same warning times. They are more sensitive than sensors and if there are problems then they can be switched to sensor mode only, but that then gives shorter warning time for fast trains and longer warning time for slow trains. This is a common thing as sometimes conditions are such that the predictor mode has to be turned off due to false activations. Turning the current up as mentioned above makes the crossing more sensitive, but also enhances the issue of a false activation, causing more issues.
CN could also add loss-of-shunt timers or enable loss-of-shunt programming in the predictors. These features have been built into most predictors since the year 2000. Siemens makes crossing signal safety products. Perhaps VIA's Venture sets will have to be equipped with Siemens shunt enhancers. Shunt enhancers are coils above each rail which induce an electromagnetic field that pushes more current through the wheels and axles, thereby overcoming contact issues and helping along the track circuit current.
THE PRESENT: REAL-TIME UPDATES OF THE EFFECT ON VIA'S CORRIDOR OPERATIONS
It's interesting that this issue has cropped up in the same week that Venture equipment operated into Southwest Ontario on VIA train Nos 71, 76, 84 and 87 for the first time in regular revenue service. Could be a coincidence. Remember this photo? In light of recent events, it makes one wonder why it was run.
It remains to be seen how VIA will handle this operationally. Some ideas for VIA:
- Bring every Venture train to a stop for 20 seconds at every such level crossing before proceeding. (20% likely, 100% effective)
- Manually flag every such level crossing (that's a lot of climbing up and down from the cab!) (20% likely, 100% effective)
- Don't use Venture equipment. (0% likely, 100% effective)
- Add additional Venture cars to Venture consists. (90% likely, 100% effective)
- Add additional LRC or HEP cars to Venture consists (would not provide adequate between-car bearing monitoring of the entire consist)
- Return sidelined LRCs to service, replacing Ventures temporarily (retrograde solution?).
- Install shunt enhancers (being tested on Amtrak with no FRA approval yet).
- Install scrubbers on Venture wheels (to clean wheel treads in the absence of brake shoes).
- Increase the current CN signal design's shunt voltage (would require CN's approval and $ to implement).
- ...other creative solutions...watch this space!
SAT. OCT.12 NOON UPDATE: Delays of up to one hour on every schedule are anticipated, a the shunt is about to hit the fan. VIA passengers with existing bookings are being contacted by email in order to rebook on a connection that builds in the anticipated delays. (Hmmm, that's just how the initial Buffer Car era was ushered in. Pet owners with existing booking being told they can't access Fido or Fluffy on the trip because the baggage car is not off limits as a buffer car!) Guaranteed bookings in the VIA reservation system have been nixed.
Here's the boilerplate text of the emails sent to passengers by VIA:
"Hello. We are reaching out to you regarding your upcoming trip on board train xx. VIA Rail Canada would like to advise its passengers that we are currently experiencing delays on certain trains due to unexpected speed restrictions imposed by CN, the railway infrastructure owner. Delays of 30 to 60 minutes are possible on trains travelling on the Quebec City-Windsor Corridor on October xx, 2024. [info on tracking the train in real time] We thank you for your understanding and look forward to welcoming you on board."
Chat text from VIA's 'message us' section of its website. The information on the potential delays is indeed the sole province of some ticket-holders as of now:
All VIA trains were on time in the Corridor Saturday. And Sunday.
SUN. OCT.13 NOON UPDATE: VIA now has a message on their service status page which reads: "We are currently experiencing delays of 30-60 minutes on certain Corridor trains due to unexpected speed restrictions imposed by CN, the railway infrastructure owner." Another chat text with VIA was less clear and helpful: "The notice you received was just to advise you of a possible delay, there may be none at all. There is no problem with the tracks they are just undergoing routine maintenance. So far everything is good, it shouldn't be too major but this is where you can track the train in real time" and mentioning the Arrivals & Departures Schedule part of the VIA website. "If there is a delay it will be indicated here even if it's before the scheduled departure time. We never know honestly, delays usually happen live in the moment if we could predict them we wouldn't be delayed lol".
MON. OCT.14 NOON UPDATE: Go Slower! Get later! Venture-equipped trains are starting to slow for crossings as prescribed by the CN document that VIA refers to. On Mondays, 12 Venture-equipped trains ply the CN Kingston Sub. On-Time Performance (OTP) ranged widely: 9, 9, 15, 17, 22, 26, 34, 35, 38, 43 and 58 minutes late. VIA No 59 departed Ottawa 45 minutes late, arriving 1 hr 17 mins. late.
Average OTP 28 minutes late.
This morning, TRAINS News Wire discussed the topic albeit with three inaccuracies:
- "Apparently triggered by one or more incidents in which a VIA Rail Canada Venture trainset failed to activate highway crossing warning devices..." [no source given]
- "VIA has standardized each Siemens-built trainsets with one cab car coach, three 'economy' coaches and one business-class car." [two economy, two business]
- Sources tell...there were a minimal number of disruptions on Saturday and Sunday, with HEP-2 heritage coaches appearing on several trains as axle-count cars. [no source given, curiously "corrected" the next day to read: "...sources were unable to confirm a report HEP-2 heritage coaches were to be used on some trains as axle-count cars."
TUES. OCT.15 UPDATE: Venture-equipped trains are still slow to start slowing. OTP varied again today: 14, 17, 35+, 38+ and 40+.
MY PREDICTIONS - BASED ON EVERYTHING YOU'VE ALREADY READ
- probable SHORT-TERM SOLUTION: Continued speed restrictions at affected crossings. Venture trains will operate at the 30-60 minute late range, as publicized by VIA to its passengers.
- probable MEDIUM-TERM SOLUTION: Lengthening Venture consists with unused Venture cars. Especially if the news media or passengers demand changes to trains operating consistently late.
- probable LONG-TERM SOLUTION: VIA was seemingly not interested in participating in the testing and implementation of shunt enhancers.
THE FUTURE - INCREASED REGULATION YOU HEARD IT HERE FIRST
It still remains to be seen whether the regulations will go higher up than CN, to Transport Canada in its oversight role in rail safety. Who knows, possibly requiring the release of a Section 19 Ministerial Order, just like the buffer cars did! Based on the text of VIA's second system notice, Transport Canada is involved. Stay tuned.
Running extra...
...to our Canadian readers, or to our American readers who like to eat turkey anytime and are just looking for an excuse. This is your weekend! In both our nations, regardless, we have much to be thankful for each and every day even if it's just a basic baloney sandwich instead of tempting turkey and all the fixings.
This Saturday morning, over coffee and the wafting of stuffing from the kitchen, I was all set to hit 'Publish' on part three of my Four Days in September six-post pop-up series. Your loss is your gain. This shunt story is a breaking story, and required you guess it, some shunting around of the draft posts ready to be published. Just a heads-up, another emerging post on VIA's August 10-hour delay involving a Venture set in Quebec will likely be another interruption to the Four Days series. Let's roll with the punches, here, or should I say shunt with the punches! Now for a joke that's perhaps better told live. Knock knock! Who's there? The Interrupting Cow! The Interrupting Cow wh....MOOOOOO!
It's not all about the 'likes' and 'views' here on Trackside Treasure. I was interested to see that sharing this post on train orders . com and Facebook, plus others sharing it to Twitter and the Urban Toronto discussion boards resulted in 1,570 views of this post in three days, the most since May 18's Ventures in Service Part 2, and 830 views on train orders . com, the most since a September 12 post about three commuter lines in Montreal being shut down!
