Pav: They are 52mm preconnected attack hoses, with 30 or 45 meters each. Probably on the ladder to be extra lengths for use by one or more of the accompanying pump crews, or - a bit less likely - for use on the ladder if a 400 LPM nozzle is called for rather than a beefier one, which would use the 75mm on the big hand cart reel for its supply.
Last possibility is for an interior attack via the ladder...
The accompanying pump is pictured on this site, and between it and this ladder the total response could have been up to sixteen firefighters, so they could have had quite a few lines at work if the water supply permitted!
Added by David L on 08 July 2011.