Minimum Radius for N&W 2-8-8-2

[nw-modeling-list at nwhs.org]

Gentlemen,
I am writing this with the help o' my son as I write in Gaelic/Anglish if I am by myself. 
I would like to know what the minimum radius for the N&W 2-8-8-2 (#2050) would be on an HO lay oot.
My son and I are getting ready to start building our new lay-out and I have the above engine built by Life-lyke (Proto 2000 series).
If there are any words out of the ordinary please accept my apologies.
Thank ye.
Yours aye,
Mac
RBMacdonald
Memphis, TN