TAN: Boiler wash out procedures (Was: Steam Boiler Filling)

[nw-mailing-list at nwhs.org]

Can someone give us a brief dissertation on locomotive boiler wash  
out procedures?  Particularly, how many wash out plugs (and similar  
devices) are there in the typical largish steam loco boiler and are  
they all removed at every wash out?

I read an article recently about doing a wash out on a preserved New  
South Wales Gov't Rys 3800 series 4-6-2.  The loco is rather light by  
US standards and it was built in the late 40s.  Its boiler has 52  
wash out plugs, including a "belly plate", which allows inspection of  
the inside of the barrel.  It was quite a production, considering  
that wash outs were typically done every 30 days, weren't they?   
Among other things, how do you dispose of a boiler full of  
contaminated water in this day and age?

(BTW, this loco and a sister run a number of fan trips a year over  
Sydney suburban lines.)

Apologies to the list keeper if this it too tangent.

pete groom (recently returned from a trip to The Antipodes)
. . .