Trench collapse rescue situations are technical and demanding. These emergencies are typically multi-hour events that require significant equipment utilization and strong logistics management for effective mitigation. OSHA and the NFPA have established safety procedures, operational requirements, and rescuer qualification standards related to trenching operations . These standards primarily focus on the nuts and bolts requirements of hazard control, protective systems, and rescuer entry activities. However, it is important to realize that logistical support of the rescue operation is of primary importance if the incident is to have a successful outcome. This article will focus on the logistical requirements of a trench rescue emergency, and will classify the functions that must be accomplished by the logistics officer. These functions are; preparation, organization, control, service, and forecast-acquisition.
Preparation is not only a primary logistics function but also an operational phase. Logistical support for trench rescue begins during the preparation phase, (which occurs prior to the event), in which equipment is routinely inspected and regular maintenance is performed. The staff at the fire or rescue station where the trench rescue equipment is stored typically performs this task. Inspection includes a visual check of lumber for warping, splitting, or other damage. Hand and power tools should be checked for general overall condition, adequacy in stock, and proper operational readiness. Power sources such as generators must be checked for proper operation and fuel supplies. Pneumatic and/or hydraulic shores should be evaluated to assure that all of the operational parts and supplies are in place and operational. Expendable stock such as spare saw blades and chains, nails, air supply, and spare fuel should be assessed to insure adequate supply.
The preparation phase is also the time to evaluate the deployment effectiveness of your storage scheme. That is, how effectively can tools and equipment be deployed from the transport vehicle and put into action at a collapse site. This is of primary importance for rapid hazard control and timely stabilization of an unshored trench. If a rescuer has to access several different compartments in order to set up and initiate ventilation of a trench, or if a large amount of equipment has to first be off loaded in order to access ground pads or shoring panels, this can be counter productive to the operation.
Storage capacity limitations of our transport vehicles often results in cramming equipment on top of each other without giving much thought to effective deployment at an incident scene. Careful analysis should be performed, looking at the equipment that is required, what is required to get the equipment in service at the incident, and the logical grouping of the equipment in storage areas for rapid deployment on scene. The typical sequence of a trench rescue can be used to brainstorm a general chronological pattern of equipment usage. The typical equipment sequence is:
1)Approach-Ground pads and a ladder (in case someone falls in placing the ground pads!)
2)Hazard control-Vent fan, power source, atmospheric monitoring equipment
3)Trench stabilization-shoring equipment, carpentry equipment, power saws
4)Extrication-digging tools, hand and power tools for extrication
5)Patient care, packaging and removal-EMS equipment, patient packaging equipment, rope rescue and retrieval gear
Careful determination of typical chronological equipment usage can help in deciding how to store tools on your rig for rapid and effective deployment at a trench incident.
Another logistical issue that falls into the preparation phase is the development of visual displays that will be carried on the trench rescue equipment vehicle. These visual displays such as OSHA shoring charts, equipment lists, inventory lists, mechanical shore sizing charts, and manufacturers tabulated data serve as information sources This information can be displayed at the equipment supply point at an actual event and used by the logistics manager or rescue officer for inventory, assignment, tracking, tactical decisions, and various other management tasks. If you already have pre-established agreements, (which you should), for specialized equipment, such as vacuum equipment, excavation equipment, and/or cranes, you can also acquire or develop charts that show the capabilities and operational requirements of this equipment. This will be helpful to the rescue officer or incident commander in planning for the approach, set up, and support requirement for this equipment if it is needed.
At a trench emergency, logistical support will be very much in demand. A variety of equipment will be rapidly required to support a trench rescue operation. It is very easy for the logistics function to be overwhelmed if it is not well organized and strongly managed. The logistics manager must identify an area large enough for setting up their operation, and quickly work to establish a well-organized work area. The work area should be large enough to allow for the access of and removal of equipment from the transport vehicle, an organized layout of tools and equipment for rapid assignment, organization of lumber, easy identification of mechanical shoring devices , and a cutting station for preparing lumber for shoring as needed. The cutting station should include a work table or saw horses for layout of materials to be cut, a power source, power saws, adequate carpentry tools, adequate lighting, and most importantly a competent saw operator who can achieve effective cuts.
There is a lot of action that takes place at the logistics work site. The logistics manager will constantly be reacting to demands for delivery of materials, cutting of lumber, and repair or re-supply of equipment. Additional staff must be assigned to assist the logistics manager so that they are not overwhelmed by demands. Additional staff should consist of at least one cutter for the cutting station, and two assistant/runners for shuttling equipment and performing service, repairs or modifications to equipment as needed.
Organization of the logistics function includes supporting the operations of the logistics work site. The logistics manager will need to forecast the anticipated length of the operation and then determine what the support requirements will be for keeping the logistics work area up and running during prolonged events. These support mechanisms will include lighting of the work area, shelter for tools, the cut station and the logistics staff, as well as food and water for the logistics staff.
As mentioned previously, the logistics function will be kept very busy at a trench rescue event. The demand for tools, equipment, shoring, and cutting of lumber will come regularly. If the logistics manager is to be effective at their job they must take strong control over the logistics function. One way to accomplish control is to limit and control entry into the equipment storage area. Setting up some type of visible barrier such as barrier tape, snow fencing, or street barricades can be effective in creating controlled access so as to direct people to a single check point for requesting equipment and supplies.
Inventory tracking is an important function that must be accomplished at a trench event. The logistics manager must know what tools have been checked out, who has the tools, and where the tools are being utilized. Inventory awareness is also required as far as having knowledge of what equipment is available on other apparatus that is on the incident scene. For example, many jurisdictions have trench rescue vehicles that primarily carry shoring and carpentry equipment. Other apparatus such as rescue companies that carry power sources, extrication tools, patient packaging, and rope rescue equipment must then support these vehicles. The logistics manager must know what equipment is carried on these other vehicles so that it can be acquired if requested.
Inventory control also requires the logistics manager to use and update the visual displays that were mentioned above. Charts that show lumber sizing and available stock should be displayed and updated as stock is added from re-supply or used up during the operation. Sizing charts for pneumatic and hydraulic shores are absolutely critical for quick reference during the selection process, especially when mixing together shores, swivels, and extensions. It can be extremely frustrating for the rescue officer when they request a 48 inch total length shore with a swivel on both ends, and receive a shore-extension-swivel combination that inevitably will be too long.
Controlling the logistics function can also be enhanced by the visual displaying of charts or white boards that list available air supply, fuel, or other re-supply needs.
SERVICE TO RESCUE OPERATIONS
So what is the primary function of logistics at a trench rescue event? Well obviously it is to effectively supply the rescue component with tools and equipment so that they can do their job. This is accomplished by assuring that the organization and control functions mentioned above are in place, anticipating the operational needs, and preparing tools, equipment, and shoring for use.
The tools and equipment that logistics must acquire and prepare include lumber, shoring materials , carpentry tools, digging and soil removal equipment, hazard control equipment, extrication tools, patient removal devices, rope and rigging equipment, generators, fuel, ladders, lighting, and heating equipment.
The preparation and distribution of shoring materials, including the cutting of lumber and the selection of proper mechanical shores, is a primary function of logistics. The rescuers will take measurements in the trench and identify the required length of shore that is needed. It is up to logistics to make it happen in rapid fashion. This is where a competent saw operator and mechanical-shore sizing charts could make or break logistics. If you send back the wrong size shore you look like a fool!
Unusual entrapment problems at a trench collapse can often create the need for modification of tools or equipment for special purposes. This may include modification to digging or extrication tools or modification to shoring panels. This has happened on several different trench rescue incidents that the author has encountered. At one event a small rock had the victim’s foot wedged and the extrication efforts required a thin digging tool for insertion between the rock and the victim’s foot. The typical small entrenching shovel or other garden trowel carried on the trench unit was too wide. We identified our needs to the logistics manager, who then cut the blade of an existing entrenching shovel down to the size required and the rock was easily removed.
The logistics manager also is responsible for supporting the ongoing rescue operations through re-supply of fuel to power tools, maintaining and re-supplying air to pneumatic tools, making field repairs to damaged equipment, and performing on site service to keep power tools and generators running smoothly.
Trench collapse rescues are frequently long-term operations that may require the services of specialized outside resources. As is true with most long-term events, re-supply of critical materials will also occur. The logistics manager must forecast what the support requirements of a long-term operation will be, and make arrangements to acquire and set up this equipment. Support materials for long-term operations include lighting for nighttime operations. Tripod lighting, specialized light units, or lights on elevated masts on fire department apparatus are some of the choices logistics may consider. Lighting must be acquired not only for the rescue area but also for the command post and the logistics work area.
Anticipated weather conditions should be assessed and arrangements made for rain and/or sun protection over the trench area to protect victims and rescuers from inclement weather. If rainwater runoff will be a problem, anticipate the need for pumps for water removal and materials for diking or diversion of runoff water away from the trench. If cold weather is going to be an issue attempt to acquire heaters that can be used to warm victims and rescuers in the trench.
Assessment of re-supply needs is a part of the forecasting function of logistics. Lumber, shoring, fuel, and air will be the primary items that need to be acquired for the purpose of re-supply when the trench rescue is anticipated to last several hours.
Difficult rescue situations such as total burials, intricate entrapment by boulders, building materials, or heavy equipment, and collapse involving running or saturated soils, may require equipment from sources not on the scene. This specialized equipment may come from internal or external resources. Internal resources might include rescue and extrication equipment from other rescue companies, ladder companies, or other fire department sources. External resources might include additional shoring, vacuum trucks, trench shields, heavy equipment, or engineering expertise that may be acquired from the local public works department or private contractors.
In these situations, the logistics function should be prepared to identify the sources and locations of specialized equipment that may be needed. The logistics manager must then coordinate with command for the acquisition of internal or external resources as needs arise.
Trench rescue events are not everyday emergencies. However, when they do occur they can challenge rescuers skills and overwhelm the incident commander with logistical support requirements. It is absolutely critical that a strong logistics officer be assigned to manage the logistics function at a trench rescue emergency. If the outcome of this type of event is to be successful, logistics must competently support the rescue effort. This requires the logistics manager to address the logistics functions of preparation, organization, control, service, and forecast-acquisition.