Central Whirinaki is a large 25 bunk hut, sleeping 11 in each of two bunkrooms, plus 3 in the large kitchen / dining area. The hut is 'serviced' category, but no firewood or gas is provided, so it's unclear what the service referred to is - maybe the presence of a warden in summer?
Large flats outside provide space for camping. there's a woodburner - wood may be an issue - the area had been stripped pretty bare when I visited. Tank water is plumbed, and the river is 20m away if you prefer a swim.
A very popular hut - I recommend a rainy midweek day in winter if you want it to yourself!
Serviced Hut
Formerly maintained by DOC, the historic Chaffey Hut is now maintained by the Golden Bay Deer Stalkers and is in good condition. Water from a side creek, fireplace, 3 bunks (one in the entrance passage)
Colenso Hut lies not at its namesake, Lake Colenso, but 5 minutes away on the terraces of the Mangatera River (south fork). It's a standard hut with 8 bunks on two sleeping platforms, a 'corker cooker' wood-stove for heat and the option of cooking, and tank water. The hut is nicely sited to catch the morning sun, with views of the sunrise over the main Ruahine Range to the east.
The Colenso basin and lake is a destination worthy of a visit in itself: an amazing array of native flora and fauna in an area which is otherwise a beech or tussock monoculture.
The Colenso name comes from missionary William Colenso who may have been the first European to cross the Ruahines. A 'Colenso crossing' of the Ruahines via Colenso Spur above Barlow Hut, Lake Colenso and Colenso Peak is a viable 2-4 day crossing of the Ruahines.
Standard Hut
Basic 6 bunk hut at Comet roadend. Just the basic 6 bunks and a bench, with mattresses and tank water. But in surprisingly good nick considering it is accessible to all vehicles.