Shop workers are masters of fabrication down at MTA New York City Transit’s Coney Island Shop. When they need a component or a part that is no longer manufactured, they – well - they make it themselves. The talent and dedication of this team combined to revitalize and vastly improve the performance of a motorized track-cleaning train that made its first pass of the system nearly 20 years ago.
NYC Transit’s pair of vacuum trains received extensive late-life overhauls. The upgrades are aimed at extending their service lives, improving the efficiency of their operation, increasing reliability and easing maintenance tasks.
Five-car, self-propelled work trains equipped with diesel motor power and high-powered vacuum cleaning systems, the vacuum trains or VakTraks were designed to remove trash and steel dust from ballasted subway track. The trains roll through the system overnight between 11 p.m. and 5 a.m., making their rounds between passenger trains and out of the sight and earshot of most subway customers.
Track cleaning is necessary for safety
Keeping the road bed clear of trash is a key element in NYC Transit’s ongoing effort to reduce track fires, and the deployment of the vacuum trains is the most efficient way to perform the task.
“The vacuum trains are extremely valuable tools in our efforts to keep the road bed free of steel dust and litter. We have overhauled the second train at the Coney Island Overhaul Shop and aside from making the improvements, we will be incorporating what we have learned in the design of the next generation of vacuum trains,” said SVP of Subways, Joe Leader.
As would be expected with such specialized equipment, spare parts for the two trains have long been exhausted and there are no more replacement parts to be had. However, what at first was a problem has since been turned into an opportunity. The Division of Car Equipment has a long history of creating specialized rolling stock to meet the needs of our subway system. But the division’s personnel also have an enviable reputation for making improvements to existing equipment.
Unlike subway cars, which are purchased in multiples of 100, the VakTraks are the only two vacuum trains built to NYC Transit specifications. Though not exact copies, as every rail system has unique characteristics which must be accommodated during design, ten other vacuum trains of different designs were built for other railroads throughout the world. But all the trains of similar vintage have since been retired from service.
“We replaced the old components with new, more reliable pieces,” said Joseph Ragusa, General Superintendent, Division of Car Equipment-Work Equipment. “The Vacuum Trains were never really what we would call maintenance-friendly equipment. So, we took the opportunity to make changes and improvements and we will take what we have learned as we design the next generation of vacuum trains.”
Work was recently completed on the VT #2 which received several system upgrades. The changes addressed shortcomings in the train’s original design, increasing reliability and improving performance.
Work results in improved braking
A major area of improvement is the air brake compressor, which was changed over from Reciprocating to Rotary Screw Type. This change alone increased air volume by fifty percent, which provides for a more dependable build-up and retention of air pressure. It will also solve the problem of broken belts, which had to be swapped out often.
Cleaning performance was another area in need of an upgrade. The vacuum operation was being adversely affected by damage to the upper suction hood assembly, which is a sheet of metal below the roof that connects the ducts to the bins. “We noticed that with everything else working properly, we weren’t getting the suction we should have been getting,” said Maintenance Supervisor Wendel Charlton. “An examination showed several holes in the upper hood assembly, which compromised the unit’s effectiveness.”
A catalogue of work
The Coney Island Overhaul Shop fabricated 12 complete dump doors which comprised of 28 individual parts to be cut, shaped and welded. They were made of steel, primed with corrosion resistant paint. Much of the debris collected is saturated with water.
Road Operations personnel ran over 300 feet of new piping to accommodate the relocation of the air dryer system. The work allowed the removal of the obsolete dryer from a very tight enclosure susceptible to temperatures extremes that contributed to premature failures.
A total of three new air dryers were installed on the train. The old dryers did not function nor were they supported by the vendor. The majority of parts for the Vacuum Trains are obsolete. New systems were in order but we had to match the footprint of the available space combined with old technology.
Two of the dryers were installed on each end of the train for the air brake system. The old dryers left water in the system causing stuck brakes conditions during inclement weather. These new dryers required 74 volts DC voltage and the head cars only had 24 volts DC, so we had to design and purchase step up transformers. The center car had a similar issue, however the voltage in that car was 220 AC so we had to not only step down the voltage but also convert it over to DC.
Two brand new compressors identical to Transit’s new R156 locomotives were installed in the head out cars for the braking system, but we had to modify the engine pulley, fabricate and install compressor frames and the drive assembly in order to obtain a prime mover.
New compressor and frame assembly was also installed in the middle car to ensure positive pressure for the vacuum system.
New electronic software was purchased and programmed to drive the Propulsion engines. The exhaust system and urea systems were removed and massive exhaust manifolds were fabricated. Brackets, a heat shield and flex pipes were custom made and electric hook ups required running new wiring to create the interface.
New copper tubing was routed to all of the valves, reducing hydraulic ruptures and increasing suction damper door operation. All train line electrical cables were split apart and thoroughly cleaned and redressed. Rotted pneumatic hose were changed out and new a new feature was installed to override any stuck brake condition.
New rubber flex tubing was installed between the newly fabricated lower suction damper and the upper suction damper. The roofs were disassembled in order to remove two gigantic chutes which were fabricated by reverse engineering and replaced with components crafted from stainless steel. All 252 filter bags were replaced with new ones to improve the vacuum suction. Several corroded panels and brackets were replaced with fabricated pieces.
The work was accomplished in house by a team of workers who routinely build and modify equipment to fill the unique maintenance needs of the New York City subway system. So, the next time you see a yellow-painted train trundling through the system, remember that a lot of work and dedication went into its rehabilitation.