Evacuation Platform Research Articles

A numerical study on smoke propagation in metro tunnel fires with different door opening scenarios

Abstract Numerical study was carried out to analyze the effect of door opening scenario on the smoke propagation in metro tunnel fires. The smoke back-layering length, critical velocity, and temperature distribution were studied under a total of 8 working conditions. Results show that the opening of emergency exit doors could result in a shorter smoke back-layering length in the train compartment. In such conditions, a smaller driving force was needed to approach the critical velocity. On the other hand, the high temperature area of the tunnel evacuation platform would change under different opening scenarios. The research result could be used as a deeper understanding of the smoke propagation of metro fire and a reference for the formulation of smoke control.

Study of spatial temperature features of road tunnel fires under multiple factors

AbstractAfter a highway tunnel fire, the rapid change of the internal ambient temperature directly affects the personal safety of pedestrians. Based mainly on the lateral possibility of fire location and considering the coupling effect of multiple factors in a two‐lane highway tunnel, this study systematically carried out 63 full‐size tunnel fire simulation studies relying on Fluent software. The smoke temperature distribution patterns in the transverse and longitudinal spaces of the tunnel after the fire were revealed. This study shows that the smoke temperature below the tunnel vault is susceptible to the effect of sidewall restraint, making the maximum temperature of the tunnel vault of the offset fire source large; considering the lateral location of the fire source, the maximum temperature prediction formula of the tunnel vault is modified to expose the change law of the longitudinal temperature decay of the vault. This paper reveals for the first time the law of temperature distribution changes at the characteristic height of the human eye on the evacuation platform in the tunnel; the systematic study of the fire source cross‐sectional temperature distribution changes at the key lining structure points, and it is found that a low‐temperature space conducive to personnel escape exists in the lower part of the tunnel away from the fire source side. The results of the study are beneficial to the design of safe evacuation paths in the tunnel and the active emergency evacuation of personnel in the near‐fire source area.

Deep reinforcement learning based train door adaptive control in metro tunnel evacuation optimization

Passenger evacuation in a metro tunnel is affected by distinct factors in the environment; thus, it is a huge challenge for both designers and managers throughout the metro system’s life cycle. A lateral evacuation platform is usually designed in a modern metro tunnel, and its evacuation efficiency is directly affected by train door opening strategy. By comparing the strategies of opening one, two, three, and four train doors, it is found that opening more doors improves evacuation efficiency. However, when two or more doors are accessed, this can lead to congestion on the evacuation platform near the train door. To reduce the congestion and improve evacuation efficiency, an adaptive train door control policy is proposed in this study, which features an adaptive dynamic programming method, namely, deep q network (DQN). The information of the environment and the state of the train doors are selected as the input and output of the control policy. By simulating scenarios under random, sequence, and DQN policies, the evacuation efficiencies are detailed. Results show that the proposed adaptive control method effectively improves evacuation efficiency. This method helps overcome the disadvantages associated with the fixed train door opening strategy and provides an optimal train door control policy during tunnel evacuation.

Disaster emergency response framework for smart buildings

Building evacuation is critical in saving human lives in case of an emergency resulting from natural or human-made attacks and disasters. The efficiency of evacuation can be enhanced by integrating the internet of things, fog computing, cloud computing, and other communication technologies. In this study, we present an intelligent evacuation system that combines Internet of Things (IoT), fog layer, and cloud layer. First, this system applies IoT technologies to capture environmental information, and the location of occupants to track their movements. Second, the Fog layer is employed to detect emergency events using Support Vector Machine (SVM), perform real-time Spatio-temporal processing based on the data collected, and dimension reduction with the energy-saving mechanism. Third, the Cloud layer facilitates an evacuation algorithm to compute a fast and safe route using environmental and occupant information gleaned from the fog and generate an evacuation map to direct evacuees to the exit. Our model considers the current location of evacuees as well as environmental information gained from intelligent building sensors and personal mobile platforms to recommend the optimal evacuation route for each traced evacuee. The results of simulations show that our framework can efficiently and accurately guide evacuees to a safer location while significantly reducing direct fire exposure. Further, performance parameters are evaluated by comparing fog-cloud deployments and cloud only deployments for more clarity. This study acknowledges that the proposed paradigm is efficient in utilizing IoT devices, fog, and cloud services to build an energy-efficient, cost-effective, and scalable evacuation platform for smart building advancements.

P‐3.6: A training system for the rescue process of acute and severe diseases based on AR

China is one of the countries with the most serious natural disasters in the world. Hidden dangers and risks of all kinds of accidents are intertwined and superimposed, and the factors affecting public safety are increasing. It is urgent to strengthen the construction of emergency medical rescue capacity. During the nineteenth collective learning of the Central Political Bureau, general secretary Xi Jinping stressed that we should strengthen the capacity building of aviation emergency rescue and improve the airspace guarantee mechanism for emergency rescue. As the most important aerial medical evacuation platform, helicopter has the advantages of fast response, strong mobility, wide rescue range, direct arrival at the first line of treatment, etc. it has become an important means of modern rescue, and also the only way to open life treatment in case of land damage. From the international experience, the helicopter emergency medical system established by most developed countries plays an important role in disaster relief and anti‐terrorism. China has a large population, complex terrain and uneven regional development. In case of disasters, the casualties are often more severe and the demand for treatment is more urgent. It is urgent to establish an aviation medical emergency rescue system suitable for the national conditions and with helicopters as the main carrier, and accelerate the research and development of key technical equipment.In recent years, more and more people realize the necessity and benefits of the application of interactive technology for aviation medical simulation training in major events and disasters. Interaction refers to the transmission and exchange of intelligence, data, data and technical knowledge in all aspects of nature and society. From the perspective of information theory, local chronicles are a tangible text information carrier, which collects all kinds of information in a certain region. Interactive technology is to use certain means to achieve the purpose of interaction, and gradually enter the era of multi field application! In thefield of aviation medical rescue, it is in urgent need of penetration and integration.This paper mainly develops an AR emergency rescue process training system. Through the creation of data sets, action recognition based on computer vision and deep learning, the selection of recognition model and action capture, the action is recognized based on AR, and then 22 joint points of human hand and upper arm skeleton are taken to label the data space position. Through the above learning results, we can get the real‐time hand recognition based on depth information Upper arm skeleton output. Neural network is used to recognize human skeleton action. The skeleton information coordinates are imported into RNN neural network for deep learning. Finally, based on the complementarity of CNN and LSTM, combined with the idea of dual stream structure network, the action recognition is carried out.

Casualty Evacuation (CASEVAC) Platform Review and Case Series of US Military Enroute Critical Care Team With Contract Personnel Recovery Services in an Austere Environment.

In a rapidly changing operational environment, in which there has been an emphasis on prolonged field care and limited evacuation platforms, military providers must practice to the full scope of their training to maximize outcomes. In addition to pushing military providers further into combat zones, the Department of Defense has relied on contracted personnel to help treat and evacuate servicemembers. This article is a retrospective review on the interoperability of the expeditionary resuscitative surgical team (ERST) and a contracted personnel recovery (CPR) team in a far-forward austere environment and will discuss actual patient transport case reviews that used multiple evacuation platforms across thousands of miles of terrain. To effectively incorporate CPR personnel into a military transport team model, we recommend including cross-training on equipment and formularies, familiarization with CPR evacuation platforms, and mass casualty (MASCAL) exercises that incorporate the different platforms available.

Time to Rescue for Different Paths to Survival Following a Marine Incident

The time required for rescue is a critical factor for surviving a marine incident. The regulatory framework, International Maritime Organization (IMO) Polar Code, utilizes a risk-based approach. It states that the vessel operators are to define the time required for rescue but never less than 5 days. Based on experience from the classification society DNV GL, utilization of the minimum requirement of five days is the current industry standard when conducting risk assessments. The dimensioning of search and rescue resources is a national issue. There are no international requirements defining the adequacy of the resources for different geographical areas. The remoteness and lack of resources present within the IMO Polar Code area imposes a significant challenge for mariners in distress. The time required for rescue is highly dependent on multiple variables. Based on this study, the number of persons to be rescued, the number and type of evacuation platforms and the distance each evacuation platform must travel significantly impacts the time required for rescue. In addition, the meteorological and oceanographical (metocean) conditions play a significant role when determining the efficiency of a search and rescue operation.

Agent-based simulation of hindering effect of small group behavior on elevated interval evacuation time along urban rail transit

Passenger evacuation on elevated rail lines has always been a challenge for rail transit safety operation and evacuation planning. Though the importance of passenger behavior to evacuation has been recognized gradually, limited research focused on the influence of small group behavior on evacuation of elevated rail transit system. This paper conducted a questionnaire survey about passenger willingness of small group behavior in elevated interval evacuation firstly. Then, an elevated interval evacuation with different small group proportions, small group gathering status and the design of interval evacuation platform was simulated using multi-agent-based model, and the influences of small group behavior on evacuation were analyzed quantitatively. Three types of evacuation time, namely t-train, t-risk, and t-total for passengers alighting from trains, leaving from risk area and exiting from the stations respectively, was calculated and compared in with and without small group conditions. Results indicated that the small group behavior show a stronger hindering effect on the long and narrow evacuation walkway platform which induced dramatical increase for total evacuation time. When the interpersonal maximum distance equaled 1 m, t-total could be increased by 64.9% in unidirectional evacuation and by 52.0% in bidirectional evacuation compared to where interpersonal maximum distance equaled 2 m. Besides, relatively narrow evacuation walkway may deteriorate unidirectional evacuation condition sharply than bidirectional evacuation. Considering the significantly hindering effect of small groups on elevated interval evacuation, it was suggested that small group behavior should be taken into consideration seriously in evacuation plan and evacuation facility design in the future.

Fire characteristics of rescue station inside railway tunnel with semi-transverse ventilation

Rescue stations are essential in long railway tunnels to provide a safe, smoke-free refuge for evacuated passengers in the event of a fire. The fire characteristics of rescue stations with semi-transverse ventilation are significantly different from those with longitudinal ventilation. In this work, the fire characteristics of a rescue station with semi-transverse ventilation are studied using numerical simulations. The numerical method is verified using 1:20 scale model experiment. The dependencies of the temperature and visibility on the smoke exhaust velocity, fire source position, and piston wind are discussed in detail. The results demonstrate that the smoke temperature distribution at the top of rescue station is related to the fire source location. When the fire source is under the shaft, the maximum smoke temperature at the top of the rescue station decreases with an increase in the smoke exhaust velocity; when the fire source is in the middle of two shafts, the maximum smoke temperature is independent of the smoke exhaust velocity. When the smoke exhaust velocity is 3 m/s, all of the smoke is controlled between vertical shafts no. 2 and no. 4. This conclusion is significantly different from that of longitudinal ventilation. On the evacuation platform of the rescue station, the smoke exhaust velocity has little influence on the smoke temperature distribution, and the temperature at a height of 2 m can meet the specification requirements of lower than 60 °C for a 20 MW fire source. Moreover, the piston wind has an influence on the visibility of the evacuation platform, which is another obvious fire characteristic for semi-transverse ventilation.

U.S. Military Medical Evacuation and Prehospital Care of Pediatric Trauma Casualties in Iraq and Afghanistan

Background: Traumatic injuries were the most common reason for pediatric admission to military hospitals during the recent wars in the Middle East. We describe injury characteristics and prehospital interventions performed on wartime pediatric trauma casualties in Afghanistan and Iraq, stratified by medical evacuation platform. Methods: We queried the Department of Defense Trauma Registry (DODTR) for all pediatric (age < 18 years) encounters from January 2007 to January 2016. The DODTR is the data repository for all trauma-related injuries managed by deployed US military medical treatment facilities with surgical capabilities. We requested all documented prehospital care, which may have been delivered anywhere from the point-of-injury until a fixed-facility with surgical capabilities. We stratified subjects according to Centers for Disease Control age groupings: <1 year, 1–4 years, 5–9 years, 10–14 years, and 15–17 years. Results: Of the 3,493 pediatric encounters in the DODTR, 1,004 underwent military evacuation from the point of injury: 911 (90.7%) by standard medical evacuation platforms and 93 (9.3%) by nonstandard, improvised evacuation assets. Six hundred seventy-five of the 1004 pediatric trauma casualties were between 5 and 14 years of age. Over 75% were male, over 80% were in Afghanistan, and most were injured by explosives. Across all age groups, serious injuries to the head/neck and extremities were most common. Subjects transported by standard evacuation platforms underwent tourniquet application (12.2% vs 5.3%, p < 0.05) and intraosseous access (12.2% vs 4.3%; p = 0.02) more frequently than those on nonstandard platforms. Casualties evacuated by nonstandard platforms underwent airway adjunct emplacement more frequently those on standard evacuation assets (3.2% vs 0.3%; p = 0.01). IV access and opiate administration were the most commonly performed interventions on both standard and nonstandard assets. Subject survival to hospital discharge was 88.1% on standard platforms and 89.2% on nonstandard platforms (p = 0.75). Conclusions: Approximately 30% of pediatric trauma casualties in Afghanistan and Iraq underwent medical evacuation from the point of injury directly to a military treatment facility with surgical capabilities. Most of those children did not undergo the prehospital interventions studied. Future investigations evaluating pediatric medical evacuation and prehospital care, medical staffing, pediatric-specific training, and equipping of pediatric-specific materials may be beneficial.

Numerical simulation of fire smoke in extra-long river-crossing subway tunnels

With the gradually increasing number of river-crossing tunnels in recent years, the risk of tunnel fires continues to rise. Therefore, the fire-smoke control effects of different tunnel structures and ventilation and smoke exhaust systems should be studied. The Fire Dynamics Simulator was used to simulate fires in segments with different slopes in Nanjing Metro Line 10 by considering single-hole single-track and single-hole double-track structures. Moreover, variations in temperature, CO concentration, visibility, and the settling height of the smoke layer were analyzed in detail. The results show that, in terms of temperature, CO concentration, and visibility in the −28‰, +8.9‰, +28‰ tunnels, the single-hole double-track tunnel structure has certain advantages. However, in the −7.5‰ tunnel, the single-hole single-track tunnel slightly presents lower risks than the single-hole two-track structure, whereas the settling height of the smoke layer is higher. In general, the fire risk closely associated with the gradients, and results show that the hazard for the section with positive gradient (+8.9‰, +28‰) after a fire were lower than those for the section with negative gradient (−28‰, −7.5‰). Simultaneously, the fire risk is related to the location of the fire due to different serious consequences under different fire scenarios. Comparatively, the damage caused by fire in section −7.5‰ tunnel is the greatest. In terms of the tunnel's own structure and internal facilities, the single-hole double-track tunnel contains an evacuation platform, fireproof doors, and other emergency facilities, so it is a safer choice from the viewpoint of personnel evacuation. In short, combining related parameters after the fire revealed that the single-hole double-track structure is more suitable in the actual design and application processes.

Numerical and experimental study on the flow field induced by a train urgently speeding to the rescue station

To simulate the unsteady airflow variations in the main tunnel, transverse alleyways and pilot tunnel of the rescue station as a train with emergency is speeding towards the rescue station, a numerical model using dynamic mesh technique for the train running to the rescue station was carried out. The dynamic variation analysis of velocity field and pressure field in the rescue station reveals some airflow behaviors. Experiments have been conducted in parallel and efforts have been done in order to verify the validity of the simulation by comparing with the experimental data. The results show, when the train runs towards the rescue station, the airflow variations perform complexly. Before the train decelerates, the positive pressure occurs in the whole rescue station, and the highest relative pressure occurs in the main tunnel, so the airflows in transverse alleyways blow from the main tunnel to pilot tunnel with 6.2m/s of the highest average velocity. In the earlier stage of train’s deceleration period, the airflows in transverse alleyways 1–4# reverse their direction and reach −2.5m/s of the highest average velocity. When the train stops in the rescue station, the velocity of airflow in the evacuation platform area blowing from the rear to the front of the train varies between 9m/s and 12m/s, now the pressure difference between the main tunnel and the pilot tunnel is obviously less than that in the period of constant speed, and the airflows in transverse alleyways still blow from the main tunnel with higher pressure to the pilot tunnel with lower pressure, with 3.7m/s of the highest average velocity. As the train stops further, the pressure difference diminishes gradually, so does the airflow velocities in the evacuation platform area and the transverse alleyways, which decreases to 3m/s and 1.9m/s respectively when the train has stopped for 5min. It is suggested that more attention should be paid to the impact which the airflow field variation produced by a train urgently speeding to the rescue station has on the fire smoke diffusion.

Crowd Evacuation Simulation Based on WebGIS

In order to improve the efficiency of people evacuation from hazardous regions and reduce the ill effects of disasters, a distributed decision support system for large scale crowd evacuation is proposed. The system is supported by the technology of Web Geographic Information System (WebGIS). Basically, by analyzing the system framework we may acquire a novel approach to establish a distributed large-scale crowd evacuation platform for emergency management. Research results show that the proposed system is useful for devising evacuation plans in advance as well as real-time management under disaster.

Fresh Whole Blood Transfusion for a Combat Casualty in Austere Combat Environment

There are many challenges to treating life-threatening injuries for a healthcare provider deployed to a remote location in a combat setting. Once conventional treatment protocols for exsanguinating hemorrhage have been exhausted and no medical evacuation platform is available, a nonconventional method of treatment to consider is a fresh whole blood (FWB) transfusion. A FWB transfusion can be a life-saving or life-prolonging intervention in the appropriate setting. The authors present the case of a combat casualty in hypovolemic shock and coagulopathy with delayed medical evacuation to a surgical team. While the ultimate outcome was death in this case report, the patient arrived to a surgical team 15 hours after his injury, alert and oriented. In this scenario, FWB transfusion gave this patient the best chance of survival.

Improvements in the Hemodynamic Stability of Combat Casualties During En Route Care

Three Forward Aeromedical Evacuation platforms operate in Southern Afghanistan: UK Medical Emergency Response Team (MERT), US Air Force Expeditionary Rescue Squadron (PEDRO), and US Army Medical Evacuation Squadrons (DUSTOFF), each with a different clinical capability. Recent evidence suggests that retrieval by a platform with a greater clinical capability (MERT) is associated with improved mortality in critical patients when compared with platforms with less clinical capability (PEDRO and DUSTOFF). It is unclear whether this is due to en route resuscitation or the dispatch procedure. The aim of this study was to compare prehospital Shock Index (SI = heart rate / systolic blood pressure) with admission values as a measure of resuscitation, across these platforms. Patients were identified from the Department of Defense Trauma Registry, who were evacuated between June 2009 and June 2011 in Southern Afghanistan. Data on platform type, physiology, and injury severity was extracted. Overall, 865 patients were identified: 478 MERT, 291 PEDRO, and 96 DUSTOFF patients and groups were compared across three injury severity scoring (ISS) bins: 1 to 9, 10 to 25, and 26 or greater. An improvement in the admission SI was observed across all platforms in the lowest ISS bin. Within the middle bin, both the MERT and PEDRO groups saw improved SI on admission, but not the DUSTOFF group. This trend was continued only in the MERT group for the highest ISS bin (1.39 ± 0.62 vs. 1.09 ± 0.42; P = 0.001), whereas a deterioration was identified in the PEDRO group (0.88 ± 0.37 vs. 1.02 ± 0.43; P = 0.440). The use of a Forward Aeromedical Evacuation platform with a greater clinical capability is associated with an improved hemodynamic status in critical casualties. The ideal prehospital triage should endeavor to match patient need with clinical capability.

Analyzing the Future of Army Aeromedical Evacuation Units and Equipment: A Mixed Methods, Requirements-Based Approach

We utilize a mixed methods approach to provide three new, separate analyses as part of the development of the next aeromedical evacuation (MEDEVAC) platform of the Future of Vertical Lift (FVL) program. The research questions follow: RQ1) What are the optimal capabilities of a FVL MEDEVAC platform given an Afghanistan-like scenario and parameters associated with the treatment/ground evacuation capabilities in that theater?; RQ2) What are the MEDEVAC trade-off considerations associated with different aircraft engines operating under variable conditions?; RQ3) How does the additional weight of weaponizing the current MEDEVAC fleet affect range, coverage radius, and response time? We address RQ1 using discrete-event simulation based partially on qualitative assessments from the field, while RQ2 and RQ3 are based on deterministic analysis. Our results confirm previous findings that travel speeds in excess of 250 knots and ranges in excess of 300 nautical miles are advisable for the FVL platform design, thereby reducing the medical footprint in stability operations. We recommend a specific course of action regarding a potential engine bridging strategy based on deterministic analysis of endurance and altitude, and we suggest that the weaponization of the FVL MEDEVAC aircraft will have an adverse effect on coverage capability.

A New Models for Emergency Evacuation under the Disaster Condition

Abstract. People must face many disasters every day, which cause losses in property and human lives. It is significant how to establish the emergency evacuation model and for high density population in large areas according to the actual situation of their emergency evacuation. This paper put forward a Multi-levels Emergency Evacuation Model (MEE) based on the collective evacuation for high density of population in large areas under the earthquake condition in China, which firstly find the best ways from the multi-gathering points(Origins) in the disaster area to multi-settling points(Destinations )in the safe area based on the road impedance such as the traffic, road speed limit and pavement damage to weight the evacuation ability of road network, and secondly determine the evacuation auto numbers on the every routes which is at the target to deliver all the evacuating people from the Origins to Destinations in the shortest time. The experiment area is Dezhou city in Shandong province of China, and an emergency evacuation platform was put up according to the multilevel emergency evacuation model using Google map API and C# as development platform, and the result show us that MEE is promised to be a new methods for emergency evacuation.

The Future of Vertical Lift: Initial Insights for Aircraft Capability and Medical Planning

The U.S. Army continues to evaluate capabilities associated with the Future of Vertical Lift (FVL) program-a futures program (with a time horizon of 15 years and beyond) intended to replace the current helicopter fleet. As part of the FVL study, we investigated required capabilities for future aeromedical evacuation platforms. This study presents two significant capability findings associated with the future aeromedical evacuation platform and one doctrinal finding associated with medical planning for future brigade operations. The three results follow: (1) Given simplifying assumptions and constraints for a scenario where a future brigade is operating in a 300 x 300 km2, the zero-risk aircraft ground speed required for the FVL platform is 350 nautical miles per hour (knots); (2) Given these same assumptions and constraints with the future brigade projecting power in a circle of radius 150 km, the zero-risk ground speed required for the FVL platform is 260 knots; and (3) Given uncertain casualty locations associated with future brigade stability and support operations, colocating aeromedical evacuation assets and surgical elements mathematically optimizes the 60-minute set covering problem.

Lessons Learned: Operation Anaconda

With the recent long deployments of our military, a review of lessons learned becomes a vital part of mission success and helps to shape our forces for future conflicts. This article examines some medical issues that were experienced by the Raider Rakkasans of the 101st Airborne (Air Assault) Division during Operation Anaconda in Afghanistan. Topics include nutrition, altitude sickness, medical evacuation requests, and the evacuation of wounded on resupply platforms (back-hauling). When nutritional aspects of war fighting were discussed, an emphasis was placed on making a greater variety of field rations accessible to the force with the addition of a multivitamin to each ration. Also, a meal high in caloric content before infiltration and an education/inspection program to ensure the maximum benefit of each ration was reviewed. The use of acetazolamide to combat altitude sickness was also discussed. Dosing of 250 mg BID 24 hours before a rapid assent, then 125 mg BID for 4 days was suggested. Line three of the medical evacuation request was also reviewed for reporting inaccuracies. Complete physical examinations and direct dialogue between medical personnel and commanders was stressed. Last, a standard medical package to accompany any resupply during hostilities was advised, instead of releasing ground medical personnel to attend the wounded when using this for an evacuation platform.