Aside from the IC, an Entry Team, a Back-up/RIT Team, and a Safety Officer, you need to have adequate medical personnel on scene to monitor and treat responders. I think we can all agree that as emergency responders, we should have at least a BLS Ambulance on scene, if not an ALS Unit. Examples of other positions that you should consider filling would include an air monitoring & ventilation group, hazard control group (lockout and tag-out, energy control, etc.), rigging group, and medical group (for patient treatment, independent of the rescuer treatment/monitoring unit).
As important as these groups are, there is one other assignment that is extremely important during these types of calls: the Staging Officer. Let me recommend to you the early establishment of a staging area that is within a reasonable distance from the incident, but not so close that the units begin creeping toward the scene. Bring your resources to that staging area and keep them there until you need them. Take it from someone who has been there before, there's no feeling like arriving on scene and turning around to find six companies on location and awaiting assignment. Give yourself a brief moment to digest the information and draw the resources to fill the assignment; don't let them push you into a hasty decision. As a really smart chief once said, "What's worse than one bad plan is TWO bad plans".
As you can see, a confined space incident can begin to take on a life of its own pretty quickly and if not managed aggressively, all kinds of things can go wrong. Confined space incidents are very dangerous and yet often appear innocuous. As the first arriving officer to a confined space emergency you must establish an early framework for the team to follow to provide for accountability and to divide the work into manageable segments.
In our next article, we will discuss the formation of incident action plans for confined space incidents.