US Coast Guard Uses an MTNW Running Line Tensiometer for R&D

Through one of our partners, Dillon Quality Plus, the Coast Guard purchased and used our HRT-3mm Running Line Tensiometer (or line rider) to measure the cable tension loads during some qualification testing on an improved rescue hoist for the Coast Guard H-65 Dolphin Helicopter.

An HH-65C flight crew hoists an injured hiker to safety from a mountain peak in WA at an altitude of 6,300 feet.

The hoist was improved by adding a clutch designed to release if the cable forces exceed a known value.  The Coast Guard tested the release force pulling on the cable at various speeds from 1 in/s to 30 in/s.  After the hoist passed this testing, the Coast Guard then conducted a number of drop tests that consisted of a 600 pound mass attached to the end of the cable and various amounts of slack in the cable from 1 to 5ft.

During all testing, the tensiometer (or dynamometer) was attached to the cable and the load output was recorded.  The HRT-3mm system worked perfectly.

The HRT-3mm is designed to measure running line cable tension loads from 0-13,000 lbs.  It only weighs 30lbs and is compact but reliable.

Tags: cable tension monitoring, calibration, Coast Guard, HH-65C, HH-65C Dolphin Helicopter, Injured Hiker, Line Rider, Line Tension, Running Line Tensiometer, Search and Rescue, tensiometers, tension meter, winch payout, winch tension

This entry was posted on Wednesday, February 17th, 2010 at 3:34 pm and is filed under Line Control Systems. You can follow any responses to this entry through the RSS 2.0 feed. Responses are currently closed, but you can trackback from your own site.

Cable Tension Meters (or is it Tensiometers or Dynamometers?) for Barges, Rigs, Construction, and Pipeline Inspection.

We often get asked questions about the difference between tension meters, tensiometers, and dynamometers. There is good reason for the confusion because many different industries use the same words for different applications. For example, the word tensiometer, which we use to describe our primary cable tension/payout monitoring equipment, is also used to describe a soil moisture monitor, and dynamometer is a word that was widely used within North America for a device for measuring automotive horsepower.

At Measurement Technology NW we focus on measuring cable tension in many different applications (from 1,000 lbs-1,000,000 lbs) and we use the words tensiometer (dynamometer) and tension meter interchangeably. Even though the words mean much the same thing, our tensiometers can be provided with an extra sensor to measure payout and speed – two line control parameters that are not always considered when referencing a standard “tension meter”.

Tensiometers can be of two main styles; running line tensiometers (RLT’s) are designed to ride the line and provide measurements of tension, speed and/or payout as the line moves through the unit. Static tensiometers are devices that clamp onto to non-moving lines and only need to provide a measurement of line tension.

Our customers use MTNW tension monitoring devices in applications such as: offshore mooring, barge mooring, oceanographic payload monitoring, ROV launch and recovery system monitoring, tethered pipeline inspection (or pigging) monitoring, etc. Usually it is a safety requirement that drives the procurement of these tensiometers.

Here is a picture of a barge mooring monitoring project for which Ombak Marine Group in Kuala Lumpur has installed a group of MTNW’s tensiometers. These units are defined as tensiometers (or dynamometers) because we are helping them measure all three line parameters.

Our running line tensiometers are 3 sheave devices that detect tension by the deflection of the strain gauge transducer installed in the load pin that is in the center of the top sheave.

Here is another picture from an NPCC barge mooring monitoring project. NPCC, based in Dubai, ordered 8 running line tensiometers (or dynamometers) from us. You can see how we have installed this device in a compact area under a platform. It is tethered from above to avoid damage in a slack line event and tethered fore and aft to prevent rocking.

Whether you call it a tensiometer, a tension meter, or a dynamometer (and hopefully we’ve cleared away some of the confusion), we build the most rugged, accurate, and easily installed cable tension monitoring device in the industry.

Tags: cable tension, cable tension monitoring, tensiometers, tension measurement, tension meter

This entry was posted on Tuesday, January 12th, 2010 at 9:37 pm and is filed under Line Control Systems. You can follow any responses to this entry through the RSS 2.0 feed. Responses are currently closed, but you can trackback from your own site.

Flowserve Selects MTNW Tensiometers (Dynamometers) for Decoking System Retrofits

LCI has recently provided Flowserve Corp. with tensiometers and LCI displays for monitoring the operational status of their decoking systems. Coking is an oil refinery process that consists of heating a heavy oil stock in order to “crack” its long-chain hydrocarbon molecules into usable distillate components, leaving behind a product known as petroleum coke. Coking is often done in dual-drum units that are up to 30 feet wide by 150 feet tall. Some coking units produce as much as 5,000 tons of coke per day. Refineries normally have 2 to 4 of these units operating continuously, but newer refineries can have up to 16 units.

Petroleum coke is a hard, porous, charcoal-like substance that is used in many commercial applications, but getting it out of the drum is difficult. For over 100 years Flowserve has specialized in high-pressure coke cutting tools designed to remove finished coke and prepare the drum for its next processing cycle. Flowserve’s most recent cutting head and pump produces 4,500 psi with 1,200 gpm throughput that can cleanly empty a coking drum with only 2-4 hours of automated cutting. Imagine cleaning your sport court or house deck with that!

However, during this process cut coke chunks will often fall down on the waterjet head and trap it in the drum. To alert operators of this condition, Flowserve chose MTNW’s 3-sheave 20KIP tensiometers (dynamometers) to understand where the jet is in the drum (line payout), how fast the jet is being lowered (line speed) and how much weight is on the jet (line tension). We worked closely with our load pin manufacturers to ensure that these tensiometers were intrinsically safe for this refinery application. This kind of accurate line control data allows operators to increase both personnel and property safety factors.

Tags: cable tension, decoking system, dynamometers, tensiometers

This entry was posted on Monday, September 21st, 2009 at 11:00 am and is filed under Line Control Systems. You can follow any responses to this entry through the RSS 2.0 feed. Responses are currently closed, but you can trackback from your own site.