Chip Macdonald is the President of Best Safety, LLC., which provides Contractor Safety Pre-qualification, and on-site OSHA/MSHA training and consultation to AFL-CiO affiliated industrial contractors and labor unions throughout New England, New York (NYS Bldg. & Const. Trades Council), New Jersey Pennsylvania and Ohio. Chip has over twenty years experience in teaching high-angle rope rescue and confined space rescue.


As a Technical Rescue Professional and Safety Trainer and Consultant specializing in OSHA/MSHA/FRA, I’m pleased to say that the FreeTech™ Harness, designed and manufactured by CMC/ROCO, will undoubtedly set a higher design standard for all ANSI Class III full body harnesses in the near-future. Now that this harness with its patented sit-posture, repositioning device is a reality, we in the S&H industry cannot ethically continue relying on the semi-effective, after-market technology of “relief straps” (R-straps) to prevent or even delay the cardio-pulmonary debilitation of suspension trauma (ST) any longer. With R-straps, too much is left to proper installation, timely initiation and exhaustive execution by the victim of a post-arrested-fall. As such, R-straps only slightly improve the chances of survival at the expense of extensive physical effort expended by the orthostatic victim. Once you are physically bound in a vertical orthostatic posture by a standard full-body harness, the harness immediately reverses its life-saving function by efficiently:

  • Gravitationally draining 5-6 liters of total blood volume into both legs within minutes of arrest via the femoral arteries (with muscle walls);
  • Setting double tourniquets on terminal impact by constricting leg straps at the groin to prevent return venal flow to the heart via the subcutaneous femoral veins, collapsed (without muscle walls) beneath the constricted leg straps;
  • Rapid heart rate, pumping the heart empty of blood (10 oz.), severely damaging hypoxic heart muscles which then decrease pulse rate and drop blood pressure;
  • Rupturing heart valves and tearing ligaments requiring hydraulic back-pressure in all 4 heart chambers to function properly;
  • Increasing numbness, paleness of skin, cyanosis, and loss of vision and hearing and muscle tremors as peripheral (non-essential) blood flow decreases and stops;
  • Distending femoral veins in the legs to 16X volume, prolonging liquid diffusion of plasma into interstitial leg tissues, as these waste products accumulate causing the onset of dangerous systemic acidosis;
  • Plasma diffusion leaving toxic blood solids behind in the femoral veins, causing extensive deep vein thrombosis (DVT). These clots block the tricuspid valves from functioning properly as “rest stops” between heart beats for venal blood returning back against gravity to the heart from the lower legs.

OSHA’s maximum 1,800 lb Terminal Impact Force (TIF) encountered during an arrested fall using a shock-absorbing lanyard is equivalent to the force your body would experience from your seat belt upon running your vehicle head-on into a concrete bridge abutment at 15 mph. Except that this force unfortunately accumulates in the groin.   You only have to hang for a few minutes in a FBH from a tripod (without any slamming effect) to realize how much effort is required to functionally operate single or double stirrup R-straps. A healthy 25 year-old male in reasonable physical shape is often sweating profusely and breathing hard within minutes of being suspended. With any post-arrested fall there is also the potential for harness-induced pathology (HIP):

  • Harness-induced groin injuries (scrotal tears, crushed or ejected testes) due to a damaged harness or ineffective pre-use fit-testing, leading to further blood loss,
  • A nauseating, spinning,15º pitched hang-angle hyperflexing the neck muscles, further constricting critical blood through the carotid artery leading to brain hypoxia,
  • Vascular acidosis combined with low blood oxygen levels detected by the Vagus nerves suspended in the carotid artery may signal the respiratory center of the brain to eventually slow (or interrupt) autonomic breathing (dyspnea or the “gag response”);
  • Any free fall which involves striking objects on the way down, may have the effect of reducing the lanyard’s energy absorption capability and limiting its deceleration distance, thus potentially resulting in a TIF considerably greater than the maximum allowed 1,800 lbs.

Beyond these physiological effects, psychological effects and systemic shock can also be problematic after an arrest. Panic and isolation can paralyze the injured victim, costing valuable recovery time. These all add up to real-time deterrents to vigorously exercising the “muscle pump” of the legs, meant to force sluggish venal blood flow past dozens of clotted vein valves and double leg garrotes. Once the exercising has begun, it should continue until technical help arrives. Even though it could mean ultimate survival, the last thing a debilitated post-arrested-fall (PAF) victim may desire to do voluntary is deploy, don and exercise in an R-strap. Until today, that was our primary option for PAF self-rescue.


In most self-rescue (SR) ops, there is a plan option to “shelter in place” whenever it is feasible and does not pose a greater hazard. But how exactly can one wait safely for either a second-party assisted rescue (AR) or a third party technical rescue (TR) team to access the hang site, when time, physical distress and shock are immediately working against the self-rescuer.

I have studied technical high-angle rope and confined space rescue techniques, and trained building trades and fire schools for two decades. What I have learned is that there are basically two options for everyone after a fully-deployed arrested fall: 1) to either be rescued promptly; or 2) to succumb to the syncope (fainting) cycle, where the terminal faint is inevitably beyond recovery. With the advent of the FreeTech Harness, a third alternative is available. A qualified person designing a personal fall arrest system (PFAS) now has the option to equip workers at height with a harness fully capable of providing an immediate point-of-refuge for anyone, anywhere, at any time. With its two-stage Switchpoint™ System, anyone properly trained and wearing the FreeTech Harness can, within seconds, deploy from pelvic restraint in a vertical orthostatic posture, into a comfortable point-of-refuge in a sit-position harness.

The qualified person (QP) for fall protection in ANSI /ASSE Z359.0 is defined as:

“A person with a recognized degree or professional certificate and with extensive knowledge, training and experience in the fall protection and rescue field who is capable of designing, analyzing, evaluating and specifying fall protection and rescue systems to the extent required by this standard.”

Under the requirements of ANSI Z359.1 Safety Requirements for Personal Fall Arrest Systems, Subsystems and Components and with the knowledge of the terminal effects of a fully deployed 18-plus foot arrested fall from anchor point, the QP must select a feasible method which does not create a greater hazard in order to protect those working on an elevated, unprotected surface greater than 6 feet above a lower level. With the FreeTech Harness I am no longer concerned with meeting the minimum Federal requirements of a qualified person responsible for “specifying fall protection and rescue systems to the extent required” by ANSI. This new harness recovery technology is a game-changer in the PFA market when it comes to offsetting the effects of suspension trauma. It is my assessment that when used according to the manufacturer’s instructions, the FreeTech Harness with its SwitchPoint System is capable of eliminating many of the thousands of unnecessary deaths and injuries incurred from arrested falls resulting in prolonged orthostatic suspension while awaiting rescue.

Chip Macdonald
President, Best Safety LLC