Mines Rescue Service Ltd (MRSL) is a partner in this project, part funded from the EC Research Fund for Coal and Steel (RFCS), set up following the expiry of the ECSC treaty, through contract RFC-CR-03010.
The project was intended to examine how arduous climatic and environmental conditions impact on workers, together with investigating how climate issues affect the successful outcome of emergency activities. The overall objective of MRSL’s work was to provide an improved understanding of the ability and shortfalls of working, emergency procedures and rescue as depth and distances increase in coal mines. The project was due for completion by the end of February 2007.
During the final phase of work, three mine trials were carried out underground on the modified BG4 breathing apparatus with the rehydration system and personal microclimate cooling jackets. Core body temperature and heart rate were monitored for each team member to obtain pre-test, mid test and post test values. The core body temperature results for personnel wearing the modified BG4 sets with the rehydration system all demonstrated little or no increase, whereas the cooling jackets were essentially of no benefit.
An initial draft of an emergency rescue heat management methodology was developed during the year. CFD modelling for visualisation aids and application to mine heat modelling was also progressed further, with equipment surface temperatures measured underground being input.
This work provides a strategic continuation of earlier work undertaken for HSE by MRSL and reported in HSE Research Report 180 - Use of self-rescuers in hot and humid mines. This earlier work addressed a recognised research 'gap' concerning the practical limitations, and ultimately personal endurance limits associated with the extended wearing of mining industry respiratory protective devices under high physiological stress conditions. This work confirmed that thermoregulatory problems could arise when directly evacuating hot and humid mines. It was identified that those undertaking a long distance evacuation in conditions of high heat and humidity could be at additional risk from heat strain and that the design of emergency response strategies should take this into account. It was also identified that there was a requirement to provide a satisfactory means of simulating the hot air experience of an escape respiratory protective device in use.
The work within this project addresses these requirements directly by researching the design of a hot air device suitable for training and research purposes, together with investigating various strategies to control body temperature in severe conditions of heat and humidity. These strategies are a direct reflection of the potential benefits of installing safe havens - that is, offering a place of relative safety where mineworkers can rest, recover and rehydrate, and then continue their evacuation as part of a managed, staged evacuation process.
The work comprises two principal components; firstly the thermal behaviour of a filter self-rescuer operating in a carbon monoxide challenge atmosphere was extensively modelled and inspired air conditions computed. This work confirmed that existing device approval standards inadequately account for heat tolerability testing. The analysis work led to a hot air simulation device being developed, based on a new absorbent “reactive plastic cartridge” (RPC) technology. The device offers inspired air heat levels comparable to a filter self-rescuer operating in a ~1% carbon monoxide atmosphere. Extensive testing of the device was undertaken by HSL and supporting medical risk assessments were provided by RPS Business Healthcare in conjunction with MRSL staff. Discussions were also held regarding the possible supply of a training version to industry.
The second phase of the work, scheduled for completion in mid-2007, involves physiological trials using MRSL’s chamber at Rawdon. This work will use a cohort of medically supervised subjects, who will exercise under simulated evacuation thermal conditions, allowing various cooling and recovery strategies to be evaluated.