Shackle Load Monitoring Design Challenge (closed)

Shackles are a key hardware component in lifting and rigging because they are the connection between a load and a sling in many lifting operations. Shackles come in various sizes and strength. Each one is secured with a pin and bolt. For safety reasons, it is imperative to use lifting system components within their design operating limits. Because they are so commonly used there have been attempts to incorporate real-time load monitoring into shackles. The solutions that have been implemented to date have a number of downsides that have limited their use. They tend to be too fragile to withstand the environment in which they are typically used and they require large wireless transmitters that can interfere with operations during use.

Shackle Load Monitoring Design Challenge Entry Form
Shackle Load Monitoring Design Challenge Release Form

The Challenge

In this design challenge, you will help us design a new wireless load measurement system for industrial pin shackles (typical load capacities are on the order of 5-10 tons). We are asking you to think outside the box and design a system that advances the state-of-the-art in this area.

The challenge will be conducted in two phases:

  • In the first phase, we expect participants to submit conceptual designs with rough-order-of-magnitude estimates for size, power, weight, and bill-of-materials (BOM) cost. At the end of the first phase, we will select up to three participants and award them a prize of $1,500 each.
  • If the quality of the Phase I results merit the continuation of the challenge, award recipients will be invited to participate in an optional second phase. In this phase, the participants will develop a working prototype. We will provide each of finalist team with three 12.5-ton capacity Crosby Alloy Bolt Type Shackles to use for prototyping purposes. These are given as an example of a typical size shackle, but the solution must be scalable to any size shackle. At the end of the second phase, we will select a winner and award the winner with a prize of $7,500.

System Requirements

Any system to read the load and transmit the data is acceptable that fulfills the following requirements:

  • Wireless transmitting range of 150 ft (50 m) minimum
  • Sampling frequency of 1 Hz or better when the system is under load
  • Load reading range from 10% to 200% of shackle rated capacity
  • Maximum load measuring error of ±5% of actual load within the entire load reading range, stable over a one-year calibration cycle
  • 10 lbf (44.4 n) precision of load reading
  • Battery life of >1 year without replacement or recharging
  • Load sensing and transmitting components are rugged and weatherproof enough for extended outdoor use.

Judgment Criteria

In addition to meeting the minimum requirements, the following criteria will be used to judge the entries:

  • Compactness of load sensing and transmitting components
  • Durability of load sensing and transmitting system
  • Simplicity of software interface between receiver and transmitter
  • Stability and accuracy of load reading
  • Total cost of system, with preference given to low cost components on the shackle
  • Extended wireless range beyond the 150 ft (50 m) minimum
  • For Phase 2 prototypes, quantitative measurements of how well the prototype matches the Phase 1 performance estimates.


Phase I deliverables include:

  • Design documents
  • Bill of materials including rough pricing (assume quantities of 100)
  • Performance and product development estimates, including:
    • Power use at full rated load, no load, and system sleep
    • Battery life
    • Load reading range
    • Measurement error across the load reading range
    • Precision across the load reading range
    • Dimensions
    • Weight

Phase 2 deliverables include:

  • Updated design documents
  • Updated bill of materials including rough pricing (assume quantities of 100)
  • Prototype system to include:
    • Sensing unit attached to the sample shackle
    • Receiver unit (preferably, connected to a PC laptop using a USB connection)
    • Software for real-time readout of measured loads (for the PC laptop)
  • Performance measurements for comparison with Phase 1 estimates
  • Updated product development estimates


  • The challenge is now closed.

Design Challenge Rules and Conditions for Participation

The Design Challenge is open to anyone without restrictions. Participants may be individuals or teams. As a condition of participation, each participant shall sign a Shackle Load Cell Design Challenge Release Form granting rights to Telact for each submitted design for purposes of evaluation. Telact will negotiate IP rights with invited participants of the (optional) second phase.

Participants are responsible for all costs of design and development, including the shipping of Phase 2 prototypes to Telact. Telact shall provide each Phase 2 participant with three sample shackles at its own expense.

The Design Challenge will be administered by Telact. The PHM Society is not responsible for the execution of the challenge or the selection of winners. Any questions, entry forms, or submissions sent to the PHM Society shall be discarded.

Phase 1 and Phase 2 challenge winners will be decided by Telact, LLC at its sole discretion. Telact reserves the right to not select any winners or offer any awards in case no submissions are received that meet the minimum technical requirements.

In the spirit of fairness, selected questions and answers will be posted on this page on a regular basis.