Measuring Tension on Static Lines
This article is about using Crosby Straightpoint’s Clamp On Line Tensionmeter (COLT) for measuring tension on static wire ropes and guylines.
It was co-authored by two individuals that have been involved with the product for several years and continue to play a lead role in putting the latest evolution to market today:
- David Ayling, former owner of load cell manufacturer Straightpoint, and president of FAD Equipment Store.
- Wayne Wille, business development manager—technology solutions, at The Crosby Group.
A COLT is born
The COLT was launched by Straightpoint, pre-Crosby acquisition, circa 2017. First to see it was a delegation at the National Association of Tower Erectors (NATE) annual event, Unite, which took place that year at the Gaylord Opryland Resort & Convention Center, Nashville, Tennessee. We remember people queuing around the ballroom to get a hands-on experience with the product. The show generated over 120 hot leads in just a few hours.
Crosby Straightpoint’s COLT is used for measuring tension on static wire ropes and guylines.
Another primary market for the product is weighing and balancing elevator cars in new installations and maintenance or repair applications, principally because the product now connects to an app that features a new, bifunctional elevator mode. The versatile tool and app combine to measure tension on each cable, automatically calculating car weight. They can also measure and calculate balance of load across up to 10 cables. We explain more about this technology below.
Perhaps to a lesser extent, COLT has also proved its worth on:
- Pretensioned median cable barriers
- Zip lines
- Winch ropes
- Overhead electric transit wires
- Fall arrest systems
- Aircraft cables
- Utilities equipment
- Architectural wire rope installations
It has been most widely utilized in North American markets but is consumed in other geographies too.
The COLT measures tension on wire ropes up to 11,000 lbf (lb. force) / 5,000 kgf (kg force) and up to 1 in. / 25mm diameter.
Using a COLT
The COLT measures tension on wire ropes up to 11,000 lbf (lb. force) / 5,000 kgf (kg force) and up to 1 in. / 25mm diameter. It clamps onto pre-tensioned wire ropes, eliminating the need for additional sheaves or tooling. The tool transmits tension data wirelessly to any smart device running the Android or iOS app that also contains a cloud-based, infinite wire rope library. Tension in wire ropes can be measured and logged within a few seconds.
Removing the need for exchangeable sheaves and tooling is an important selling point and was one of several non-negotiable product features when we first sat down at the drawing board. At the time, there were a few tools already in the market that were comparatively inefficient, inaccurate, and cumbersome. If Straightpoint was to gain any traction, it had to launch a tool that solved some of the inherent shortcomings with existing solutions.
Another thing that COLT gave the marketplace, especially telecommunications infrastructure companies, is traceability and accountability. It enabled these firms to implement audit trails where it was impossible to do so before. Reality is (or was), in this sector, that problems arose because it wasn’t always easy to track installation, inspection, and maintenance work, particularly in remote locations, where much of the installed base of towers is.
Another primary market for the product is weighing and balancing elevator cars.
Given the nature of work in this sector, where wind and other elements are of critical concern, a notable feature of the updated COLT is its ability to automatically fetch local weather conditions (temperature, wind speed, and wind direction), which is added to the data in the logging report, available on a cell phone or smart device. This is in addition to the app already grabbing GPS coordinates.
Other standout features of the COLT app include:
- Camera-enabled, allowing jobsite photos to be tagged into reports
- Cloud-based, color-coded, wire rope database
- The ability to save a logging file as .pdf or .csv
- Simulation mode to allow training and experimentation while in the app
- A self-calibration facility added for customers using the calibration verification rod (see below*)
- An additional datalogging facility that averages out several readings
Many of these were recent enhancements to an already great product. They are features that our customers have asked for—and we’ve delivered.
The versatile tool and app combine to measure tension on each cable, automatically calculating car weight.
Note that all the wire ropes in the database are stored on a cloud server; when you install the app it downloads the database. As Straightpoint adds new wire ropes to the database, you will get those added to your app—for free!
What do end users say?
We’ve had countless reports from jobsites about how COLT has saved time, enhanced safety, added traceability, etc. But one that stands out, we saw first-hand when we caught up with a customer that uses the product and app to weigh and balance elevator cars.
Before using COLT, it took two people an hour to complete measurements on a single elevator, utilizing a special clamp, come-a-long, and a load cell. Now, that has been cut to a single person being able to complete the same job in 10 minutes. Yes, that’s a 50-minute and whole person saving. Think how that transfers to an entire team working for a whole day, week, month, and year.
Users also point out the ergonomics of the 23.2 in.-long, lightweight tool, which weighs just 7.7 lbs. In fact, one customer told us that they had cut their hand on an alternative solution in trying to work out how it should be used.
Users point out the ergonomics of the 23.2 in.-long, lightweight tool, which weighs just 7.7 lbs.
You don’t get far in the telecommunications sector without addressing the needs of the stakeholders represented by what we call the Big Three:
- Crown Castle, a real estate investment trust and provider of shared communications infrastructure.
- American Tower Corporation, a global provider of wireless communications infrastructure.
- SBA Communications Corporation (SBA), an independent owner and operator of wireless communications infrastructure including towers, buildings, rooftops, distributed antenna systems (DAS) and small cells.
Crown Castle even put the COLT through rigorous testing in line with industry documentation, the Telecommunications Industry Association (TIA)-222 Structural Standard for Antenna Supporting Structures, Antennas and Small Wind Turbine Support Structures. COLT had to (and did) pass numerous tests with multiple units on several different wires.
The tool transmits tension data wirelessly to any smart device running the Android or iOS app that also contains a cloud-based, infinite wire rope library.
Prior to that, COLT had been tested extensively by Straightpoint, including repeatedly dropping it from height onto concrete and retesting to make sure that it remained accurate even after impact. We remember this testing well; the product was dropped multiple times at different angles from a height of 10 ft. onto a solid concrete base. After each session of drop tests the COLT was tested for accuracy—and passed.
This store also stocks Crosby Straightpoint’s calibration rod that allows COLT to be checked for accuracy in the field, with guaranteed accuracy up to 365 uses. The operator clamps the rod into the COLT and then selects the 'Cal check' mode within the app. The app will then check the accuracy of the COLT and pass / fail that calibration is within 3%.
The app will also count how many times the rod has been used—each rod has a unique serial number.
Removing the need for exchangeable sheaves and tooling is an important selling point.
As with all products stocked here on the store, we have wrapped up a few frequently asked questions (FAQs)—and answers—to help people make final purchase decisions. Here are some we get asked most often:
Is the COLT supplied with a case? Yes, COLT was originally (and still is) supplied with an aluminum flight case.
Do I need to change sheaves if I switch rope diameter like other products on the market? No, the COLT’s unique design means that only the sheaves that are fitted to the product during assembly are needed for any rope up to 1 in. diameter. The adjustment for different rope diameters is done by a quick adjustment of the center sheave height from positions one, two, and three. It takes seconds.
Is the app expensive? No, it’s free! You can download for iOS or Android devices, and it even has a simulate mode so you can try the app before your purchase the COLT.
A notable feature of the updated COLT is its ability to automatically fetch local weather conditions.