If this is todays' subject then I have come in at the right time. I am a BAI and I've just got home after running a BA guideline drill.
I totally agree with the over-riding comment above that those that have gone before and tragically in some cases lost their lives, have been significant contributors to the procedures and equipment we use today and we shouldn't forget that or allow ourselves as individuals, regardless of the policies of the organisations we work for, forget that solemn fact.
With regard to turn round times; at today's exercise this issue was raised by the two members of the third team to enter. They were engaged in a methodical search using 6m personal line working off a pre-laid main guideline. Due to the complex layout of the smoke-logged structure being used it was a painfully slow process and by the time they had covered just twenty metres longitudally off the guideline the number two in the team was concerned that his cylinder contents were at the level when he would normally be expecting to turn around and head out. He was within 10 bar of the team leaders contents who took the decision to continue with the search pattern much to the disgruntlement of his number two.
During debrief the issue was raised again and I could only praise the team leader for considering that yes, you might normally consider turning around at the point the number two indicated but the pragmatics of the task they were engaged in meant that turning around, traversing the guideline back twenty metres to the EP would barely use a third of the air consumed during the methodical progress in to the structure.
However they were out before TOW and I wouldn't have been impressed with the ECO or the team leader if they weren't. As stated before the problem with TOW is that the BA team can't measure this and if they don't have telemetry or reliable radio comms (so far in this job I've never experienced consistently reliable radio comms?) there's no way of knowing or being advised by the ECO. In this case there's only one call the ECO can make if playing by the rules; rules born from the loss of firefighters past.