This is an excellent trip and one that would no doubt have been included in NFTFH had the route been discovered/excavated fully before the publication of the former in 2006. The trip includes an amazing variety of challenges: a decent sized pitch in the entrance series (Bubbles), low crawls, flat-out crawls, numerous squeezes, narrow rift passages, free-climbs, numerous pitches up and down on electron/rope ladders, a memorable squeeze in a duck, a traverse rigged above a ~13m deep pit, and several route finding issues (though these are relatively minor). The overwhelming majority of the trip consists of low to flat-out crawls. These weren’t too bad on the knees though as many of the crawls are on either hard packed dirt or else loose dirt and/or sand. It was one of the most enjoyable caving trips that I’ve done so far and one that requires a good deal of stamina – it took us a total of seven hours to complete. Rather than post a full description of the route here, it makes more sense to point those interested in discovering more details to the most excellent trip report written by Dunc and Pete following their trip there in 2009 (see the link below). It has all the pertinent details.
http://www.brcc.org.uk/reports/north/IrebyFellCavern3.pdf