Monday, 22 October 2012

Ropes for rescue

It must be said that this single item of equipment in my experience is the one that has little regard paid to it, compared to other items of equipment. When new and fresh of the reel, its silky feel and colours is something to behold, after a few uses, grubby and stuffed in its bag its forgotten about until that next time its pulled out for use. It is without question the most important part of the equipment that we shall use, “line rescue” would just not exist if the line were missing. Over the years I have used lines made from both natural and synthetic fibres, Hawser laid and braided lines, everything from “Polyprop” to Kevlar (Aramid) tape.

Polyprop rope, instantly recognisable as a blue three strand twisted rope. Found on Farms, construction sites and working boats. It has two good characteristics, it floats and its cheap! It has virtually no use in rope rescue. Also shown is polyprop, in a braided version.

Is technology on top of rope construction or can we expect something radical? I think we now have the best that is available at this present time, manufactures of rope just don’t make for the rescue market, industrial users will always be the biggest consumers. But add together sports climbing with the need for specific lines together with top class sailing and we can see advances in rope design and construction that are filtering back into rescue rope manufacture.

Rope or Line? It’s like Carabiner or Karabiner? everyone has an opinion, so this is mine. I recall back in my early days as a young firefighter, being told by an individual who had worked with rope for all his life, that rope is the generic name of the manufactured product. As soon as you cut it to a specific length and designate it to a specific use, it becomes line: well, that’s good enough for me. So to recap, manufacturers make rope and rescue technicians use lines. 

Choice of rope

The optimum rope for normal use is 11mm diameter nylon rope designed for rescue use. Strong enough to provide a good safety margin 3000Kg WLL, and be also sufficiently robust enough to withstand several years of use, providing you look after it. Weight is not such a concern, as it with sports climbing, there will always be helping hands to transport kit. This same rope must be suitable for all purposes (Controlled descent, safety line, establishing anchors and belays)


When I first became involved in line rescue work, two types of line commonly were used. An 11mm Static line for all descending/ascending and stretcher work (twin line working was not common in those days) and finally a 9mm Dynamic line for establishing belays. The latest lines using modern manufacturing techniques now offer us lines that are sometimes termed low-stretch or industrial. These lines are now the automatic choice for rescue professionals; the limited stretch makes them ideal for all our applications. The Military/Law Enforcement and sports cavers will still prefer the static lines, and for Sports climbers the 9mm dynamic, for its ability to take a fall and its lightness.

For rescue work we now have the line that most suits our needs, the 11mm Semi static in working lengths up to 200m, 400m + are available, but these are monsters to handle and heavy to transport.

Special applications call for special ropes, most of my lines are 100m lengths, that for me is the all-round working rope length, not too heavy or bulky for a rope bag. However It is vitally important for any rescue team to assess the need for longer ropes, normally 200m is the longest commercially available. Longer lengths can be supplied but are special order and delivery times normally reflect this. Ropes of one continuous length can make life such a lot easier. The task of passing a knot or adding additional line during a descent can be time consuming and tiring for the rescuer.

Rope must be seen as a consumable, a new rope can be ruined first time it is used. You must be prepared for that, both emotionally and financially, believe me. A lot has been written regarding the working life of a line, in my experience lines in daily use will be worn out and require retiring long before they reach their age limit. For the record, 5 years of regular use seems to be the figure manufacturers have adopted. For rescue teams, up to 8 years is good for me. After all, the line is not being used every day and providing the line has never been shock loaded and is well maintained (as it should be, your life depends on it) it will be OK.

In my experience teams never buy long enough lengths and this failure generally proves expensive in the long term. As a supplier of equipment, including lines, it is more profitable for me to sell you two 50m lines than one 100m line. The longer has to be the most economic choice, its always the ends, sometimes the first 15-20m that will be worn the most. Even by rotating the line regularly, eventually they will have to be cut off, generally leaving a piece only 30m long, which is has very little practical use. However the 100m line can withstand having several ends cut off and still leave you with a good working line. I see this daily on the Rollgliss systems we overhaul, a too a short line was purchased initially and as only the running end that has been ruined, the entire line has to be replaced to maintain a good working length.


Transporting ropes

Ropes should always be stored and carried in rope bags. A well-designed bag, besides being far easier to stow and handle than hanked or coiled line, will protect the line from all kinds of damage. Coiled lines will tangle or develop kinks caused by twisting the rope, I like my lines to be packed tight in a hap-hazard fashion in the bag, reducing chaffing whilst in transit, my second choice is to 'chain a rope'. Finally the environment that we work in can be harsh, it makes much better sense to wear out the bag than damage a line. A line, which is dirty, is not only destroying itself but also your hardware. Even fine grit and dust, especially the oxides from aluminium equipment can rapidly wear out metal equipment and lines alike, and once embedded it is very difficult to subsequently remove all these particles from the rope.Lines like to be kept cool, dry and in the dark. I always keep my lines in their bags, damage from Sunlight or rather, ultra violet light will degrade the line, but this takes ages, the line will be worn out long before this type of damage becomes a concern. Most important is to ensure that lines are stored clean and dry.

After each operational use, lines must be inspected for damage and washed if necessary. Apart from normal surface abrasion which is more or less obvious, the worst thing that can happen to a line is contamination by chemicals, once identified and confirmed, the line or the contaminated end must be disposed off, you just cannot take that risk. Materials used in line construction are particularly stable polymers and are affected by very few common chemicals, however, it is well known that nylon is severely affected by even quite dilute acids, and that polyesters are attacked aggressively by strong alkali's.




 Washing and inspection

Using a rope, which has become impregnated with grit, is also a recipe for disaster. Each time the rope is loaded over a pulley or squeezed through a descender a multitude of microscopic particles of grit and metal oxides are forcibly ground into the fragile yarn filaments of the kern and some weakening is inevitable. Thorough washing is important to remove as much as possible of this contamination that abrades the internal fibres of the line. A line cannot be properly inspected for any surface damage that may have occurred until it has been cleaned. Superficial dirt can be removed by simply sloshing the rope around in running water, avoid hosepipes or a Pressure washer, as these may force dirt into the core of the line.


For effective cleaning, lines can be washed in a washing machine, normal wash temperature 40C. Chaining the lines can prevent tangling. Other items, webbing or harness can be stuffed it into a mesh wash bag. Adding normal amounts of a fabric softener is useful and acceptable as it replaces the yarns normal Teflon / anti-static lubricants that are used in the manufacturing process.

Regular machine washing is not harmful to the line, remember that the same fibre used in lines is that found in ordinary clothing, which is designed to be washed every few days. I always us a detergent, it helps the cleaning process, but look for PH neutral types, I have used soap flakes in the past but have been disappointed with the results. I also ensure the lines go through a full rinse cycle, which I feel is important.


Pictured is a double jacket rope ( Orange over Black) laid over a four strand braided kern. The double jackets give excellent wear characteristics but the two mantles were prone to slippage. This is easily resolved by soaking the rope to induce shrinkage and pulling the wet rope through a descender a few times whilst under tension. Unfortunately many manufacturers have dropped this excellent design.

After washing, lines should be carefully inspected for damage or signs of excessive wear. The best method is tactile (time consuming) it consists of running the rope through the fingers a little at a time, flexing it into a bight and feeling for soft spots or areas of reduced diameter as well as looking for the more obvious mechanical damage.

The line should be allowed to dry naturally in a well-aired place, and then re-bagged but only when absolutely dry. Pack a damp line at your peril.


New ropes
There is a good reason why new rope's are best soaked before use. It shrinks the rope (up to 5% on cheap semi static) and this serves to compact the sheath and tighten it onto the core, improving it's wearing properties. This procedure also helps prevent sheath slippage during the first few time used, until sheath and core are properly bedded together.

Soak the rope in clean water, drain and squeeze out surplus water by pulling the rope through an anchored descender. Repeat process two or three times, each time pulling the rope through the descender in the same direction. Hang the rope up to dry for a few days. If the sheath has crept along the line, hot cut new ends to prevent any unravelling, ensuring you do not cut off the line’s CE identification, if unavoidable you will need to replace this label.

Marking lines


Lines must be marked with a CE number, but other useful information may be to indicate length, year put into service and serial number for record keeping. We mark our lines with bar codes; you can have so much information in a very small space. It is important that this information remains with the rope throughout its life. There are many different methods of marking, the main criteria being durability and that the information is always legible.
My preferred method is to mark the line both ends on coloured heat shrink tube (the colour denoting year in service. The information is written on this with waterproof ink, and protected by a transparent heat shrink tube, sealed with a hot melt adhesive tape. This type of marking is extremely durable and is removed only by cutting the line.

PVC tape can be used on its own (I have read much of the action of the solvent in the adhesive damaging the line, but providing the tape is applied to the very end of the line, it will do no harm). Finally, held firmly in place by transparent heat shrink tube. This method works but, in practise a film of dirty water seems to creep beneath the heat-shrink sleeve and eventually obscure the figures unless sealed with hot melt tape.


Rope, showing the braided and twisted three strand construction together with the data tape that runs the entire length.

Figure of 9?

What makes a good knot? it must be easy to tie, easy to untie and not damage the line, finally it must reduce the breaking strain of the rope by an absolute minimum. Remember, when a rope breaks it invariably breaks at the knot! Widely recognised as one of the strongest knots, the figure of 8 is first choice amongst rescue professionals. Unfortunately only 1 out of 10 who claim to be able to tie the knot can do so correctly. Have you ever tied this most basic knot, had it fully loaded and noticed that one or more turns in the knot have been left loose?
 
 

The most common of all the knots used in rope rescue. Tied on a single rope it makes an excellent stop knot, more commonly tied on the bight, it forms a secure attachment point. When tied "re-rove" it secures the rope directly to an anchorage point.
 
 

The sequence to tieing a good knot is easy, just follow the following order:
 
 
  • Choose the right knot for task
  • Tie the knot correctly leaving sufficient tail for a stopper if required
  • Dress the knot, ensuring the lay of the rope is not twisted or crossing over each other
  • Tension the knot, easing all parts snugly together
  • Check the knot visually


The figure of 9 knot, it's just the figure of 8 with an extra turn (8+1=9) hence the origin of its name. The knot is perhaps 1% or 2% stronger than the figure 8. Such a small margin it's not worth worrying about.
 
 

Figure of 9 (top view)
 
 

We do have figure 9 knots on our rapid deployment kits. The knot is pre-tied and tensioned. It takes a little longer to dress this knot and ensure that none of the lays are twisted.
 
 

Figure of 9 Bottom view
 
 

Suspension Trauma update

Advice for first aiders responding to harness suspension incidents


Following completion of an evidence based review of published medical literature, HSE has clarified guidance on the first aid management of a person falling into suspension in a harness who may develop 'suspension trauma'.

The key recommendations are:


No change should be made to the standard first aid guidance for the post recovery of a semi-conscious or unconscious person in a horizontal position, even if the subject of prior harness suspension.

No change should be made to the standard UK first aid guidance of ABC management, even if the subject of prior harness suspension. A casualty who is experiencing pre-syncopal symptoms or who is unconscious whilst suspended in a harness should be rescued as soon as is safely possible.

If the rescuer is unable to immediately release a conscious casualty from a suspended position, elevation of the legs by the casualty or rescuer where safely possible may prolong tolerance of suspension.

First responders to persons in harness suspension should be able to recognise the symptoms of pre-syncope. These include light headedness; nausea; sensations of flushing; tingling or numbness of the arms or legs; anxiety; visual disturbance; or a feeling they are about to faint. (Motionless head up suspension can lead to pre-syncope in most normal subjects within 1 hour and in a fifth within 10 minutes.)

Monday, 12 December 2011

RESCOM Communications

I am sure you have all seen, read or used Con Space wire communications, I most certainly have and was very impressed with its performance. However sooner or later something better comes along. I was first introduced to RESCOM by an American friend of mine and what surprised me about this system was that not only was it a full wire communications set but, this system was built into a full specification 11mm diameter kernmantle line! 

The entrants head set with the amplifier box and throat microphone. The Amplifier box has its own AA batteries and volume adjustment












 
Fully waterproof providing a choice of one or two earphones and a very responsive throat microphone. The system shown here can be worn over a BA face mask head harness comfortably. Also by not now requiring microphone connections directly into the face mask, it does not infringe the certification of the BA set. This can prove costly to have re-certified should adaptions be required to take external communications equipment.

The head harness of RESCOM has a mesh fabric which reduces its profile making it very comfortable and secure when worn beneath a helmet.


The earphone sits nicely between the straps of a Petzl Ecrin, the push fit connectors will easily part if any section of the connecting cable becomes snagged.


The set worn by the communications officer consists of a choice of either a simple headphone set with a boom mike or the choice of the full head set to be worn beneath a helmet if in a hazardous area. The amplifier has its own battery supply, volume adjustment and an on - off switch. As the system is powered at both ends its maximum working length is 1.5Km!
 The Boom mike is noise cancelling and as such must be within 6mm of the operator’s mouth. The entire system is extremely resistant to external interference, allowing it to be used in close proximity with VHF and UHF radios and mobile cell phones. The manufacturing company offer a wide range of interfaces, allowing connection to portable radios or even public telephone systems.


Without a doubt the equipment is special because the entire system utilises an 11mm kernmantle line to carry the wires. The line is as flexible as any line we have used. We have tried a wide range of hardware on the line including several Fig 8 descenders, auto stop descenders, ascenders and Gibbs, prussic loops. We have run the line through pullies and used Z rigs. The rope also takes all the usual knots very well. This rope we recommend, be utilised as your safety line. When ordering, ensure you order long lengths of line to reduce the need for knotting. 

Rollgliss Top 350 Safety Instructions

The new Rollgliss TOP R350 range of devices has been developed following experience in manufacture, maintenance and marketing of safety and rescue systems, inspected and certificated to meet or exceed the latest technical and safety regulations it has been granted the approval of the CE mark EN0158.

It complies with EN341,
EN361, EN795, EN1496, EN1497, EN1498.  It is also manufactured in accordance with OSHA, ANSI and NFPA standards.

Strict observance of the following operating maintenance instructions is essential.  Failure to comply with the present instructions will result in Rollgliss and its subsidiaries refusing to accept any liability for damages.

The required visual and functional load tests must be carried out each time the equipment is used.  To guarantee required safety standards, it is forbidden to modify the system from its original state either in part or in full.

If you are in any doubt about the condition or mode of operation of the equipment then the system or parts thereof must be replaced without delay and before the equipment is used.  Such work must be carried out exclusively by the manufacturer or by a Rollgliss authorised agency.

For the reasons of safety it is important to discontinue to use a system or a component part that has been subjected to strain as a result of a fall and to return the system, or component part to the manufacturer or to a Rollgliss authorised agency for servicing and renewed certification.

The system rope must not be exposed to any acids, alkaline solutions or any other harmful substances and should not be exposed to prolonged UV rays or sunlight.

Rollgliss should also be consulted if there are any doubts as to the possible effects of environmental or industrial agents upon the equipment.

It is in principle, possible to disinfect the system.  Approval for the disinfection procedure or disinfectant should first of all be obtained from Rollgliss. Weak solution of Savlon, rinse well in clean water.

The equipment or system may only be operated by trained and experienced individuals, who have been appointed or directed by the owner of the system for this purpose.

The owner of the system shall be responsible for setting a policy regarding training and for all visual checks and functional load tests, which are to be completed by the user.

These operating and maintenance instructions must be observed and followed with absolute precision before using the Rollgliss TOP R350 Rescue and Safety System.
Practice and regular training are essential, as personal injury may be suffered as a result of misuse of the equipment.

Visual checks and functional load tests are required each time the equipment is used.

When practising, the use of an additional protection against a fall is strongly recommended in case the equipment is operated incorrectly.


 


Note:

1 to 1 system         1 person (95Kg)
3 to 1 system         1 person ascending or 2 persons descending
5 to 1 system         2 persons ascending or 2 persons descending



Rollgliss assistance winch shown with a Jumar braking aid. The winch conveniently clamps onto the leg of a tripod and will work on square or round leg tripods. The winch has a full EN 1496 class B certificate when used with the Jumar breaking aid. If buying winches many do not have this EN requirement

Head assembly of the Rollgliss Tripod showing the four separate anchor points.

Assessing risk

Management of Health & Safety at Work Regulations 1999Regulation 3 of the Management of Health & Safety Regulations 1999 (MHSW) requires employers to carry out suitable and sufficient Risk Assessments.

So what are Risk Assessments?
A Risk Assessment requires that you assess all the risks in your workplace. That is, what could cause harm to yourself, your employees and members of the public, and the likelihood of an incident occurring. You then need to decide what precautions you must take to prevent this happening, or how to reduce the risks to an acceptable level.

Hazard and Risk
Which is which?

Hazard
means anything that can cause harm (e.g. falling from a ladders, falling down a shaft, tripping over a rope, failure of an item of equipment).

Risk
Is the chance, high, medium or low, that somebody will be harmed by the hazard. What does suitable and sufficient mean? - The detail required in the risk assessment should be proportionate to the severity of the hazard or risk. In deciding the amount of effort you put into assessing risks, you have to estimate whether the hazards are significant, and whether the precautions you have taken have reduced the risk to an acceptable level.
The five step process:

STEP 1: Look for the hazards.

STEP 2: Decide who might be harmed and how.

STEP 3: Evaluate the risks and decide whether the existing precautions are adequate or whether more should be done.

STEP 4: Record your findings.

STEP 5: Review your assessment and regularly revise it if necessary.



Hazard & risk

Hazard & risk are often confused.
HAZARD: is the potential to do harm
The hazards include...

Access to sites, projections, manual handling, working at height, uneven/slippery surfaces, ladders, noise, weather e.g. snow, ice, wind, rain, fog, sun, extreme temperatures. Biological hazards such as bird droppings, animal faeces and bacteria in air conditioning units. Substances such as dust in vents, soot and grease in flues & chimneys, asbestos. EF Radiation from antennae, especially micro wave links. Your complacency, lack of training, personal attitude, health and inappropriate clothes

RISK: is the likelihood of that potential being realised, combined with the severity of the consequences.

The risks include...
Collision injury, strains, workplace slips, trips, falls, falling objects, hearing loss,  sunburn, blown off a roof, lightning, hatches/doors blown shut. Biological such as Psittacosis, tetanus, hepatitis, Weils disease, Legionnaires disease, HIV Substances causing asphyxiation, cancer, respiratory & skin disorders

Risks can be controlled but hazards cannot be controlled
Levels of risk
High: The risk is intolerable and urgent action is required
Medium: The risk in this area should be reduced as low as reasonably practical.
Low: Broadly acceptable, existing controls are adequate.

* Ensure safe access & egress
* Design & build installations to high standards
* Provide adequate information and training
* Implement safe systems of work
* Maintain high standard of working environment
* Empower all employees
* Protect the public

There is no standard technique for carrying out a risk assessment. However, any risk assessment should satisfy three basic requirements. It should be structured, systematic and thorough. There are a number of techniques that can be used for hazards identification and analysis, depending on the degree of detail for the assessment and degree of human involvement in the process/activity.

There are two general approaches to risk assessment. These are:

* Workplace-based approach in which hazards presented in different parts of the structure or workplace are identified and then the question is asked as to who may be exposed to each hazard and when.
* The task-based approach, in which an individual or group of individuals are followed in their work activities and hazards associated with each step of their task are identified. This approach is based on task analysis.
The task-based approach to risk assessment is more appropriate to climbing/rescue activities.
Assessment of risk, These should be considered (but not limited to) when drawing up a risk assessment

Can the risk be avoided?

What are the performance characteristics required for effective PPE?

Compare proposed PPE with the requirements in the risk assessment

Review the risk assessment regularly

Write a 'Work method statement' - how you will do the work

Write a 'Safety method statement' - what things you need to consider regarding safety, for example rescue of a casualty.