'Bilco' Doors: Entering, Ventilating Below-Grade Fires

When discussing strategic and tactical considerations for structural fires, one hot-button issue that divides many incident commanders is the use of “Bilco” doors. When they say Bilco, most people in the fire service are referring to below-grade...


Stairways in these assemblies might be compromised: Many times, these enclosures have masonry stairways that are very steep, or could have eroded away due to exposure to extreme thermal conditions (see Photo 2). There may also be a set of wooden stairs, or a wooden ladder instead, that may have burned away due to the fire in the space. Furthermore, many times the stairs are used for other purposes. This author has seen cases where residents have used the stairs as storage shelves, keeping stock and supplies on them as extra closet space. Commercial occupancies can have a variety of devices within these spaces, such as conveyor belts, roller assemblies and freight elevators for delivery of goods and equipment into the lower floors; these are devices that will impede access through this area (see Photo 3).

Making entry through the assembly: Be sure to determine how the assembly opens: it may open as a single-door assembly or it may utilize a double-door assembly that splits from the center and opens from side-to-side. Most of these assemblies are locked from within, utilizing a slide bar lock with a padlock to secure the bar in place, or a quarter-turn handle which sets a lever arm in place that is secured with a padlock.

Newer designed assemblies may also have a keyed entry door on the outside. Running a power saw, pitched at approximately a 60-degree angle vertically from the door on the latch-handle assembly side of the center door seam will cut through the slide bar, and allow access through the doors. Single-door assemblies can usually be defeated by cutting the area between the latch handle and the lower sill plate of the assembly, cutting through the lock bar. This may not be the end of the problem: many structures have secondary doors at the foot of the stairway in these spaces, and these doors can be fortified with a number of additional locks, thereby stalling the advancement of the hose team (see Photo 4).

The interior stairway door: This is a significant consideration during the fire. If this door is closed and has held its integrity from the fire, then it will provide a barrier for vertical travel of smoke and heat during fire extinguishment. If the door has been left open or has failed, then all of the steam, heat and smoke will follow the paths of least resistance and travel dynamically upwards to exposed floor areas. It is critical, no matter which way the attack is mounted, that this door is taken into deliberation and somewhat controlled (if possible) during the operation.

 

Ventilation Considerations

One major critical task during any fire is controlled ventilation. During fires in below-grade spaces, ventilating these areas will be difficult at best. When the incident commander orders the attack through the bulkhead doors, there are a few issues with regard to ventilation that must be taken into account:

Where will the smoke/heat steam go? Without control of the stairwell door, everything will travel to the upper floors, impeding escape and search operations in these areas. Another option would be to use windows in the space, but that would depend on the size and availability of the windows. Most basements have a majority of the floor area above grade, and suitable windows are usually in place to facilitate ventilation (see Photo 5). Cellars, conversely, will have limited-sized windows at best, and other options may be required to accomplish ventilation, such as cutting the floor near a first-floor window area. It may be more efficient, and safer, to advance the attack lines through the first floor, and utilize the bulkhead door assembly as a ventilation point. Most angled-door assemblies are bolted on with a handful of masonry bolts. Many times, through years of neglect and exposure, these bolted seams have weakened to a point where a company can remove these assemblies much faster than cutting a secondary hole above the fire.

Ventilation and suppression timing: Having the capabilities to assign companies to immediately vent ahead of the attack crews makes the push into the below-grade area easier on the companies making the attack. It will also make providing a large vent hole in place much faster than having to cut through flooring and subfloor assemblies (see Photo 6).

 

Conclusion

An effective incident commander needs to perform “strategic triage” – location and extent, reading smoke, needed GPM, Risk vs. Gain, etc… This is the information that a strategically competent officer is looking for, so a tactical plan can be put into place. Here is the problem in today’s fire service, in general: Strategy is the hard stuff. Firefighters are not robots; they cannot operate on “auto-pilot” for all calls! Offensive operations protect civilians, and defensive operationss protect firefighters. The world is now producing disposable cars and cardboard homes, so to speak. Firefighters are programmed early in their careers to be aggressive: it is good to be aggressive, but it needs to be properly managed. Be sure to take all facets of the situation into account when developing your plan. Make sure you are making the right call: bulkhead doors have their pros and cons. Consider the experience and training of the members of your crew when formulating a plan regarding these assemblies.