Helmet; Head Protection; Suspension System; Retention System; Blunt Impact; Ballistic Energy Dissipation Reports Examples

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Integrated Firefighting Helmet

KEYWORDS

OBJECTIVE
The object of this paper is to ascertain the safety standards of the firefighting helmets. Specifically, this paper attempts to determine if there are any upper limits to the weight of the helmets. The research will be directed to determine if there is any optimal distribution recommended for the mass of the firefighting helmets. The fabrication process will be examined which support such standards which are recommended for the safety and security of firefighting personnel.

Research Questions

Precisely, this research is conducted to determine the strengths of the firefighting helmets and the impact on users’ safety and security by wearing such helmets. In particular, the research attempts to address the following questions:
Is there an upper limit to the weight that can be safely supported by the head with regards to both short- and long-term injury?

Is there an optimal distribution of mass that would minimize the risk of head and neck injury?

Are different design criteria, in terms of loads and load distributions, required for helmets intended for women?
Introduction
It is essential that the firefighting helmet is able to withstand the accidents caused by falling of any object over the head when the personnel is busy in suppressing the fire. As the fire staff concentrate on extinguishing the fire and sometime require to enter the buildings in which the fires are caused so it is essential that the personal protective equipments (PPE) they use is of standard quality and strength. At times the helmets have been so weak that the falling object caused serious injuries despite the helmets being used. There have been cases where the helmet was not broken but the quality of the helmet was such that the impact was transferred to the head, causing fatal injuries.
The process of manufacturing the helmets is important. The fabrication process can ensure that the optimal distribution of mass is brought to the level where the risk of head and neck injuries would be minimized. The manufacturing process provided the helmet suspension system which can utilize a pad suspension system. The suspension system and the uniform distribution of the mass not even helps to cushion the impact but also safeguards against the potential injuries that can be caused on head and/or neck by the blasts, which are common at the building fire mishap. (Gallagher et. al.)
Contemporary research has also revealed that providing the pad suspensions system can be better at low velocity impacts as compared to high velocity impact. At the low velocity impacts, pad systems act as buffer between the head and the force of impact. This pad can absorb this force of the impact. But, during high velocity impacts the pad systems do not provide enough compression; so these are only able absorb only limited shock or impact. Moreover, pads are prone to variation of temperatures, which makes them harder during cold weather and softer during summers. (Cote)
This has led to the development of better shell material for the firefighting helmets. Apart from the change in the material, the need is also felt to change the suspension & retention system for safety, security and protection towards the firefighting operations. The Industrial use also necessitates the development of the new enhanced firefighting Helmets, that can provide better fragmentations & ballistic security as compared to the state-of-art current helmet technology.
The firefighting usage has therefore, explored innovation in the approach to build an enhanced helmet’s suspension & retention systems so as to enhance head safety at the occasion of low & high velocity impacts, including those coming from the blasts which may happen at the fire mishap sites. The object is to reduce the possible risks of getting concussion or skull fracture or blunt and ballistic traumas to the head as a result of this blast.

Literature Review

A Literature Review was undertaken in order to look for those sources which can help the researcher to determine the answers of the three questions. The extensive search was undertaken so as to determine the standards in helmet design, recommendation of the present research towards these standards and the future roadmap towards the enhancements of such developments. The focus was on the research objectives, which was to determine the nature of the material of the helmet which can provide sufficient security and safety from the dangers related to explosions and high temperature impacts.

So as to provide the sufficient material quality and strength the following standards have been recommended for manufacturing helmets:

• Firefighting helmets should be fabricated by the heat resistant materials like thermoplastics and must be designed to sustain high impacts caused by explosions or falling objects which are very common at the fire mishap sites.
• The Firefighting helmets must have fast locking ratchet systems so that these can be utilized so as to alter helmet’s size as preferred by the user so that it can be quickly adjusted to a most comfortable place.
• The helmets should be equipped with the fast releasing buckles along with the Fire resistant chin straps so that the straps must not wear away due to heat or fire.
• The helmets must be provided with a Face shield-visor which can slide to the most comfortable position as desired by the user internally.
• The design should be such that the Firefighting helmets should be able to protect the ears well, as the excessive heat can be quickly transmitted to the body through the ears and can cause serious burns or injuries.
• The design must be such that there is a comfortable attachment of a neck flap for further protection to avoid the neck injuries (Cote)
• The design must be such that there is additional facility to the user to be able to use a pair of goggles along with the helmet

• The Firefighting helmets should also meet the following standard EN 443 with respect to:

Color: Red: Fire Bosses
White: Crew Leaders
Yellow: Fire fighters
The sources from the contemporary research also recommends that besides following the standards, the existing helmets in-use should also follow the recommendations in the Helmet inspections:

The recommendations clearly mention that Firefighting helmet must be subjected to inspection for the below conditions:

Soiling:--so as to ensure that the view is clear through the helmets and any changes on temperature due to the effect of soiling can create some additional risks
Contamination:-which means that the helmets may be inspected to be of the required quality and strength as per the main quality standards as highlighted
Firefighting helmet must be stringently inspected for any Physical damage to the surface or the shell, in terms of having any

Crack, craze, dent or abrasions

Heat related damages
Any particular damages to the earflap
For instance there should not be any Rip, tear or cut
Any Thermal damages like spoil or burn out of the external surface paint or material
Damage or/and missing component of the suspension or retention system
Damages or/and missing component of the visor or goggle
Damage or/and missing reflection trims
Seam becomes un-sewn or/and missing or torn stitch
A¾ facemodel standard SnellSA2005 orSA2010 certifications should be used.
UTV Head’s Protections XXX:--Standard for Wild land Fire’s Operations must be used and the Helmet should meet DOT,ANSI Z90.1;or Snell:--SA2005/SA2010 Standard (Grilliot et. al)
Upper limit to the weight that can be safely supported by the head with regards to both short- and long-term injury
The resources as highlighted in the section, clearly recommend about the maximum Weight which the head should be able to sustain, minimizing the risks of the injuries. The weights of the fire fighting helmet including the attachments may not exceed 1 Kg. Also the deign should be such that it must not raise the point of the center of gravity (cg) of the helmet system. (Grilliot et. al.) The CG should be at the center of the helmet. So this should be the upper limit to the weight that can be safely supported by the head with regards to both short- and long-term injury. (Grilliot et al). The other recommendations as given in the resources which were searched pertain to the optimal distribution of mass that would minimize the risk of head and neck injury. In this category the resources clearly recommend about the protective helmet’s suspension and retention system that meets the requirements described above. The Helmet is expected, to address the expected capability so as to match blunt impacts and heat dissipation requirements, stability and optimal distribution of mass that would minimize the risk of head and neck injury. This has to be undertaken during the stages of designing & development process, including any expected fabrication consideration, taking care of the projected weight and budgeted cost. (Gallagher et. al.)
The helmets like BULLARD TRAKLITE conforms to the safety first standards. There are no external clips brackets and wires, which not only contribute to the maintaining of standards on weight as there is no extra weight, but also helps in increasing the security standard. The risks of weight imbalance and security concern which may be caused due to external accessories on the helmet are avoided by this standard brand helmet ( Bullard TrakLite).
Another Helmet brand is Dräger HPS 7000 which provides the tailor made solution for the protection of head size. It is a flexible solution which can suit for different head sizes and outfitted helmet may add to considerable security risk for the firefighter. A closely fitted Helmet is not only comfortable but reduces the risks of injuries caused from impacts as an outcome of explosion or object falling overhead. (Dräger HPS 7000).
The customized solution of this helmet makes it possible to provide different helmet for different requirements. The classic series of Dräger HPS 7000 provides the uniform weight and maximum protection as it strictly conforms to the standards related to weights as especially highlighted in the recommendation standards in Literature Review, by the contemporary research on fire fighting helmets.
Another brand of firefighting helmets Rorsenbauer, provide the upper limit standards as seen from the comprehensive tests like penetration resistant test and shock absorption tests. (Rorsenbauer). These tests ensure that these set of helmets strictly conform to the standards as highlighted in the literature review section.

Optimal distribution of mass that would minimize the risk of head and neck injury

In the light of the design parameters and the research objectives like designing the helmet which is below the permissible weight or one which has optimal distribution of mass that would minimize the risk of head and neck injury or the best suited design for the women firefighters pose the unique challenge. The total endeavors as highlighted above present the challenges to optimize the performance. It may be possible that if one attempts to focus on a particular design parameter or functionality like the area of blasts, blunts, or ballistic protections tend to be offset the optimization in other area. Additionally, the challenges are also coming from the requirements to get improved protections without impact to the weight, material distribution, reliability and comfort of the helmet shell to the user. Concept recommended take into consideration the following:
- The ability to integrate well with the current fire fighting standards for the helmet shell without further altering the area of coverage provided by the helmet shell. The desire is to provide the best solution which can optimally cover all the design considerations rather than focusing only on a single or a set of parameters. It is recommended that the weights should have a facility of easier attachments, removal and re-attachment to the inner side of the helmet shell and must stay firmly at the place whenever attached. It is also necessary that the current set of retention points must not add new holes to helmet shell so as to continue to provide the uniformity of the shell material which is must for the overall safety of the helmet. Introducing additional holes or alterations for the comfort for instance for comfortable design for women may actually compromise the security. Adding pores for heat dissipation may end up in reducing the overall helmet safety, which means that the helmet can break on heavy impact causing severe damage or injury to the firefighter.
Ballistic Energy Dissipation also should not permit the impact on force to from a ballistic event to exceed an average force impulse of 0.650lbf-s, 0.500 lbf-s when subjected by a hit by a mass of 124 grains at 1325ft/s.
-Blast Protection means that the position of the helmet must be maintained on the head at the time and after exposure to at least a 5 pound blast from a distance more than or equal to 3m.
The design of some of the Helmets like BULLARD TRAKLITE distributes the weight between the front and the rear of the helmet. This offers a most balanced solution for the lighting as well as upholds the standard practice for an optimal distribution of mass that would minimize the risk of head and neck injury ( Bullard TrakLite).
Dräger HPS 7000 brand of firefighting helmets provides standard helmet series which provide streamlined design and no external attachments so that the weight of helmet is optimally distributed. As highlighted earlier in the sections, it is necessary that the mass of the helmet is optimally distributed of mass that would minimize the risk of head and neck injury. There are many designs available like sport, maximum protection and so on. But for this parameter, the best suited model is the one which has no external attachments or a sport design. The classical series which conforms to the standards as highlighted in the Literature Review section, is important so that maximum security is provided by the property of the helmet being designed with uniformity of the mass. (Dräger HPS 7000).
Another helmet in the category is Rorsenbauer Helmet. This brand has a comprehensive set of heat radiation, flame engulfment and shock absorption test. A optimally distributed mass of helmet would minimize the risk of head and neck injury due to the impact concentration at any area of the helmet. (Rorsenbauer)

Different design criteria, in terms of loads and load distributions, required for helmets intended for women

Another interesting aspect about the design of the firefighting helmets is the design consideration related terms of loads and load distributions, required for helmets intended for women.. Major design aspects which need to be altered so that those suit for the women are pertaining to the :
Comfort:-- It means providing additional level of comfort which is greater than the standard suspension & retention systems standard in general (to be assumed to be used for men).
Additional comfort must provide more facility to control heat and perspirations built-up within the helmet. It must also avoid hot spot and pressure point coming from the prolonged usage.
For the purpose of women, the firefighting helmet must also provide additional stability:-- This means that the proposed helmet must offer an additional level of extra stability which is more than or the present state-of-art suspension & retention system. This will avoid the helmet from changing its position frequently on the head at the time of fire fighting operation or the mission.
Furthermore the blunt Impact as recommended for women must be such that the recommended helmet should be able to avoid head acceleration to exceed 150 G during any impact velocity less than or equal to 17.1ft/sec, or 20ft/sec for a minimum of 2 impact in the temperature range from 32° --to--130° F.
The new superior plastic Ultrason®E2010 HC, a BASF PESU(poly¬ether sulfone), has as of late been put to an unprecedented utilization. The PAB company, a producer of wellbeing supplies headquartered in Buzet,Croatia, is utilizing the profoundly straightforward HC variation (HC = high clarity) of this material for the visor of its extremely warm safe firefighter's cap, the FIRE HT 04. This is the first business application for this new kind of plastic.
The firefighter's protective cap and its visor – created to meet especially demanding necessities – need to oppose a temperature of 250°C [482°F] for 30 minutes without being harmed. This defensive rigging even must have the capacity to withstand a temperature of 1000°C [1832°F] for ten seconds. On account of Ultrason E's glass-move temperature of 225°C [437°F], it gives itself well for this reason. Alongside its high temperature safety, an alternate essential property of this material is its inalienable flame security (that is to say, fire wellbeing without the expansion of fire retardants). The durability of this straightforward plastic makes it extremely break-safe, even under to a great degree unpleasant conditions. The head protector and the visor can be effectively created by method for infusion shaping, so even perplexing shapes with coordinated capacities can be effortlessly accomplished. The cap measures a minor 1.2 kg, which makes it exceptionally agreeable to wear.
In building up the new Ultrason variation, BASF succeeded in improving the pro¬duction conditions in such a path as to definitely diminish the common inalienable yellow shading of the plastic, subsequently achieving phenomenal visual immaculateness. Hence, the HC sort joins high clarity with the properties that are trademark for Ultrason E: imperviousness to hydrolysis, chemicals and high temperatures.
Bullard TrakLite brand provides some additional safety features for the protection of face especially important for women. Additional aluminium brackets can be attached to the Helmet model to provided additional safety. There is a complete line of nylon or gold anodized brackets that can be easily attached to the helmet to provide additional security. (Bullard TrakLite).
Among the various helmets available, Dräger HPS 7000, is most versatile in design and provides remarkable flexibility. The range of firefighting helmets have enough flexibility to enhance the safety and security for women as desired and recommended in the Literature review section. The padded four point harness of the helmet permits safe and easy adjustments of the helmet as required during the fire fighting operation undertaken by women. The head size is also taken care as the different head size would be required. The size and features of the helmet are adjustable so that the neck and chin are can be easily and closely protected as an individual requirement. The padding made of Normex also ensures a comfortable fitting. (Dräger HPS 7000). Roesnbauer Heros Extrem brand provide maximum safety and security as required. (Rorsenbauer).

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