The hard-headed approach - advances in helmet technology
From thermal burden to visor mist tests, advances in helmet technology were analysed at a recent conference held in London, UK. Eoin Redahan reports.
It seems almost farcical to think that many soldiers trudged through World War I battlefields wearing berets. Others braved raining projectiles with mess bowls on their heads. In some ways, though, today’s models are not far removed from those humble designs.
While the latest helmets provide a high degree of protection using advanced materials, people will not want to wear them if they look ridiculous or if they are uncomfortable to wear. And, if they are not worn, then they are arguably of less use than a stylish beret. At the recent Advances in Helmet Technology conference, held at IOM3 in London, UK, delegates discussed the relationship between the helmet and its wearer and the latest technological advances.
Lieutenant Colonel Toby Evans, of the UK Ministry of Defence, offered a soldier’s perspective. ‘If you expect someone to wear a helmet all the time, you are going to have to compromise on some of the performance factors’. He mentioned the need to reduce the helmet’s thermal burden, as a soldier will invariably take a helmet off when working in temperatures of up to 50°C. He added that if it does not integrate well with equipment, many soldiers will not wear one.
On the sub-system of a British military helmet, integration could include any of the following – eye/ear protection, radio headset, night-vision, up-armouring, and chemical, biological, radiological, and nuclear protective appendages. Evans cautioned against the use of specialised helmets for different army personnel, claiming that this runs contrary to the need for each soldier to be a generalist. With integration, the burden on the bearer remains a weighty issue. As Evans noted, ‘Once you get a helmet above 1.4-1.5kg, soldiers hate it’.
Talking to Materials World after the event, Mark Helliker, of the Defence Science and Technology Laboratory (DSTL) in Wiltshire, UK, noted that improved integration could actually be of protective benefit, as some of the equipment involves being mounted onto the helmet itself. ‘We are looking at options where the components of the system can contribute to the protection of the helmet. I think we shall see a significant change in the way helmets look over the next 10 years’.
Inspector Joe Moohan, of the UK Metropolitan Police, added that, despite having an anti-misting coating, visor vision can be problematic. He said that police communication in a riot situation becomes difficult through the three millimetre-thick polycarbonate visor, peripheral vision is impeded and integrating equipment such as respirators can be troublesome. But, as one delegate noted, ‘after 12 hours wearing any helmet, you run into problems’.
Helliker noted that, ‘The most important advances have actually been in terms of material processing, to improve desirable characteristics such as ballistic performance and robustness’.
Ultra-high molecular weight polyethylene is said to have made the biggest impact in the past 20 years, with other materials such as aramids making significant advances in protection performance.
However, he mentioned that the lightweight, high yielding composite materials currently used in military helmets can cause a large amount of deformation when perforated and ‘may increase the risk of behind armour blunt trauma’. Helliker added that the impact liner incorporated into their helmets had probably, ‘saved more lives than the ballistic protection alone’.
Similarly, measures have been taken to protect against the coup and contre coups injuries that result from blunt trauma injuries. Brian Gough, Projects Director at Industrial Design Consultancy (IDC) in Berkshire, UK, said a five nation European study concluded that, ‘rapid rotational motion was responsible for 60% of motorcycle injuries’.
He outlined the development of the Phillips Head Protection System (PHPS) – Enhanced Rotational Protection, where a lubricated flexible polymer membrane is applied to the outside of the helmet to mitigate the sharp twists endured by the skull and brain. ‘The lubricant and elastic quality of the PHPS membrane on a crash helmet decreases this rotational force and reduces its effect,’ he claimed. This technology could be applied to motorcycle and American Football helmets.
Whatever the technological advances, helmet design will remain a delicate process for the foreseeable future. While protection is paramount, it is imperative that designers keep the soldier’s head comfort in mind. Evans concluded that the process, ‘has got to be design led’.
Student Design competition
The Advances in Helmet Technology conference included a student design competition, which was supported by the Materials Knowledge Transfer Network. The task was to design the next generation of police helmets. Mitch Gebbie of Brunel University in London, UK, won first prize for his MG Enforcer – Public Order Helmet Concept. The design featured a curved anti-mist visor, a polarised sun protection strip, an ear twist-lock accessory mount, a two-way radio, and an increase of impact attenuating foam at the top of the helmet for added protection.
See the feature Last line of defence in this issue for more on helmet technology and reducing behind armour blunt trauma.