• Mechanical
• Engineering
• Transportation

The Mechanical department and its employees ensure the proper and safe functioning of all rolling stock-locomotives and railcars. Their focus is on early detection and preventative maintenance, which increases equipment reliability and the safety of CN trains.

Learn about the equipment we use

Equipment	Description	At CN
Wayside Inspection System	detects unsafe operating conditions for trains. includes hot bearing detectors, hot wheel detectors, dragging equipment detectors, cold wheel detectors, wheel impact load detectors, wheel profile and specification detectors and low hose detectors. connected to a central computer that monitors data on a 24/7 basis and enables CN to track trends, react immediately to problems and to be proactive in reducing accidents.	CN's system of wayside inspection detectors is the most advanced in North America We continue to implement respacing programs to reduce the spacing of Wayside Detectors to the CN standard of 12 to 15 mile intervals.
Wheel Impact Load Detectors	catch flat spots and other imperfections on wheels which can lead to broken wheels or broken rails. CN uses the information provided by WILD sites to help assess wheel maintenance needs and to determine when it's time to set aside a car whose wheels can cause excessive damage to the track. CN has the largest and densest network of WILDs in North America.	Overload and Imbalanced Load Detection Although the WILD detectors were originally purchased to identify wheels that produced high-impact levels on the rail, CN is also using them to detect overloaded and unevenly loaded cars - a key safetyissue. CN promptly contacts customers who are not loading cars properly. Other railroads have begun to use their WILD sites for overload detection. Three new WILD sites were added in 2009 to the EJ&E as part of that railroad's integration into the CN network.
Hot Bearing Detectors	sense and report an unsafe wheel bearing temperature level on a moving car or locomotive - important information that is used to prevent derailments.	Hot bearing detectors are typically spaced at 12-15 mile intervals. The 24/7 monitoring of data from the detectors enabled us to refine our tracking of repeat hot bearings. In 2009, CN added 17 new hot bearing detectors on the BC North corridor and on the Winnipeg to Chicago corridor, part of a re-spacing initiative to reduce WIS spacing to the CN standard of 12 to 15 mile intervals on core routes. The Winnipeg to Chicago corridor is now complete. 61 hot bearing detectors were also upgraded. CN now has 751 hot bearing detectors on its system. A new central office WIS system was implemented to allow consistent tracking of suspect cars, to proactively identify hot bearing detectors requiring maintenance or repair, and to enhance CN's ability to identify mechanical failures. In 2010, five new hot bearing detectors are planned for the BC North corridor. CN will also upgrade approximately 30 older technology detectors to newer equipment this year.
Hot Wheel Detectors	detect hot or warm wheels which can deteriorate more quickly and lead to derailments as well as shorter in-service life. Cars that register three or more warm or hot wheel readings are automatically flagged for testing and maintenance.	CN continued to be proactive in identifying and repairing cars that recorded multiple hot or warm wheel readings from over 450 detectors. CN is now identifying foreign and private cars with warm or hot wheels as a pre-emptive measure to detect defective valves and air brake components before they damage the car's wheels. CN performed 12,000 more single car air brake tests in 2009 versus 2008. The tests enable CN to diagnose air brake problems more accurately and to address broken wheels and stuck brakes. A new process was implemented to identify cars that have multiple occurrences of hot wheels. We tripled the number of electronic single car air brake test devices which are strategically located across the system. We now have over 100 electronic testers that enable us to diagnose air brake problems more accurately.
Cold Wheel Detectors	provide early warnings of weaknesses in a car's brake system. CN investigates and repairs cars that record multiple cold wheel readings.	CN has four Cold Wheel Detectors located at the bottom of long grades where train brakes are applied.
Wheel Wear and Dimension Detectors	capture wheel profiles and wheel dimensions as the train passes over the sites at speeds of up to 65 mph using laser-video and strobe-video technology. Allows CN to intercept worn wheels that need replacement.	CN is updating two of its three state-of-the-art laser and strobe video scanners. It is also continuing work on a wheel wear notification system to enable it to proactively plan wheel removal.
Locomotives	Fleet renewal helps CN to improve the safety and reliability of its motive power and enhance customer service, as well as reduce fuel consumption and exhaust emissions	CN acquired 135 additional locomotives for the period 2009-2010.  These new locomotives produce 40 per cent less nitrogen oxides and are at least 15 to 20 per cent more fuel-efficient than the locomotives they replaced. The new units continue to be part of CN's multiyear locomotive renewal program.
Bridge Testing System	an exceptional laboratory on wheels loaded with state-of-the-art instrumentation that provides measurements of stress levels in critical bridge components under current and expected traffic loads. The sensors are linked to a high-speed computer with specialized software to monitor and analyze locations on a bridge span in real time.
Event Recorders	All main-line locomotives are equipped with event recorders, similar to the "black boxes" used in airplanes, which monitor and record the train's speed, braking and other functions. In case of an accident, the data in the recorder helps CN to determine the cause. We also make use of data from locomotive event recorders as part of our fuel conservation and train handling programs.

Learn about our other safety activities

Activity	Description	At CN
Locomotive Maintenance	Locomotives are scheduled for trip and general servicing every seven days, and receive a safety inspection every time they are placed on a train at a locomotive safety inspection location. Locomotives in yards require a safety inspection every 45 days. Locomotive reliability performance is tracked according to type of failure, cause and repair activity. CN analyzes the data and makes changes to its maintenance activities to improve reliability. All mechanical supervisors are required to perform four locomotive quality audits per month.
Roll-bys	During Roll-by Inspections CN employees monitor a train as it moves slowly out of the yard or intermodal terminal. They look for cars with shifted loads or dragging equipment, listen for unusual noise or try to detect the smell of hot bearings.	CN employees maintained an intense focus on the visual inspection of trains.
Roller Bearing Verification	We identify roller bearings that show signs of future failure using sophisticated wayside detector methods. The detection enables us to remove bearings before their internal failure becomes a critical factor requiring train stops, setouts and possible derailment.
Industry		CN continues to share data with the rail industry on specific mechanical-related issues, such as CN cars that show evidence of lateral instability (truck hunting) or data from the WILDs.