Turnouts, an essential railroad network trackwork component, have numerous complex, costly and labor-intensive maintenance requirements. They also have specific challenges that railroad maintenance-of-way departments have been dealing with for generations. Addressing them is critical to operating a safe, fluid and efficient network, with minimum maintenance downtime. Among these challenges:
- Switch rods, which traditionally reside in cribs, must be removed for tamping.
- Inadequate switch tamping creates an unstable track surface, leading to switch failure.
- Insulation failures can occur between two bolted steel switch rods.
- Wood headblock crossties can fail to maintain gauge and can break under the switch machine due to timber crosstie decay.
- Concrete headblock crossties can break under a switch machine due to reduced cross-section or overhung load vibrations.
As such, railroads are actively seeking opportunities to increase track stability while reducing costs.
The new Universal HST® Hollow Switch Tie from voestalpine Railway Systems Nortrak is designed specifically to address the unique maintenance and structural needs of a turnout. Pairing the Universal HST® with our Unistar HR Switch Machine creates what we believe is the most advanced and seamless turnout control system in the industry.
HST® Explained
The HST® is an advanced switch support system consisting of robust, maintenance-free formed steel crossties, high strength composite “Blue Rods,” and an optional rotary assist back-drive assembly. The crossties are redundantly insulated in all areas, ensuring no single path to shunt is allowed. They allow switch rods to be relocated from cribs into the hollow portion of the crosstie, facilitating continuous mechanized surfacing though the turnout without the requirement of removing and reinstalling switch rods. Use of high-strength composite “Blue Rod” insulated switch rods allow for a single fabricated rod to be utilized, removing the insulation failure point between two bolted steel rods. Switch plates attached to the crosstie with permanent Huck fasteners increase gauge widening resistance through the switch, with resistance exceeding 40,000 pounds. A robust, steel switch machine mounting plate is permanently affixed to the crosstie and can accommodate any switch machine.
Now, this innovative system has been vastly improved with the Universal HST®.
“Previous generations of the HST® required a specific design for each turnout size, hand, and machine position (left or right on the field side),” says R&D Engineering Manager Eric Gray. “In a situation where a switch machine was relocated from one side of track to the other, or a left-hand crosstie was needed in a right-hand turnout, the HST® had to be disassembled, reinsulated and reassembled. The Huck fasteners had to be cut off—quite a process for customers. As an example, some of our customers have been in situations where, during installation, they realize there isn’t enough room for the switch machine, and they need to relocate the machine to the other side of the track. A slight change in the field could previously delay a customer’s schedule by weeks. That’s why we developed this new design, the Universal HST®.”
“The Universal HST® provides greater flexibility to maintainers by being adaptable to dynamic installation and maintenance, offering the flexibility to use one unit for all turnout sizes, hand, and machine position,” notes Gray. “It uses a permanent, electrically isolated shim plate attached to the shell of the formed steel crosstie. Adaptable switch plates dependent on the switch size and/or hand can be bolted directly to the shim plate. To convert from one switch size or hand to another, it’s now as simple as unbolting the existing plate and replacing it with a new switch plate of the desired size or hand. This is why the Universal HST® is much more maintainer friendly, giving railroads the ability to easily stock items and convert from hand or size to another without the need to handle insulation. Everything except the running plates the rails sit on is assembled, insulated, and ready to go. The plates are bolted on and easily removed. All a maintainer needs to do is remove the plates, spin the hollow switch ties around and reinstall the plates. If you ordered plates for a No. 20 turnout and then decided you wanted to use that HST® on a No. 15 turnout, instead of having to purchase an entire system, you only need two new running plates. So now, we have one base unit that will work for any turnout.”
Perfect Pairing
The Universal HST® works seamlessly with voestalpine Railway Systems Nortrak’s Unistar HR Switch Machine. The Unistar HR offers mounting flexibility (gauge or field side, and on tunnel walls), is flood safe, and can withstand temperatures as low as -40°C (-40°F) without heater elements. With integrated end position detection, installation time is just 2.5 hours. It weighs 80% less than competitors’ switch machines and no lift assist is required. It’s non-handed design reduces spare parts requirements. MTTR (mean time to replace) is 25 minutes; MTBF (mean time between failures) is 1.5 million hours.
The Unistar HR features a Single Drive Unit with up to four drive, locking and detection setting levels for switches and MPFs (moveable point frogs)
The Universal HST® “is the ideal foundation for installing a Unistar HR,” says Vice President of Signaling Chris Nordstrom. “Since the Unistar HR is agnostic to the side of the turnout on which it’s installed, it’s a clean, easy process, a clean layout. All the electrical connections and hydraulic lines are protected inside the hollow steel crosstie. We’re getting a lot of positive customer feedback. One installation team told us it took half the amount of time as installing the same machine on a traditional wood crosstie layout, noting that it could be retrofitted into any turnout.”
The Universal HST® and Unistar HR pairing aligns with voestalpine Railway Systems Nortrak’s broader goal of positioning ourselves as a system solution provider. We offer a full range of equipment and services—from fastening products to complete switch panels with integrated monitoring systems. We bring together global expertise and experience while maintaining a strong local presence. Our North American team includes some of the industry’s top experts, and we’re proud to offer Buy America-compliant solutions.
