[Lynn Eades]

My experience is mostly with the insulated std height 20 footers.
When you put them on site make sure the doors open and close o.k. They can twist under their own weight, if they are not blocked properly. Imagine what happens when you put 20 ton in them and one corner sinks. Think about it, and plan what you want.
In my experience it pays to set them up so any water runs to the door end. The reefers (insulated 20 footers) I bought, have drain holes in the corners at the door end but if a leak is happening or develops you can see them. They generally get a hard time from the container lifters, and older ones can have leaks at the roof corners.
The insulated ones (stainless or alluminium) with the "port holes" have galvanized bases. I think they are the only ones that do. To expand on that, they are the ones used below deck on the ships, and they plug refridgeration hoses into them, at the end opposite the doors. The ones with the fridge units in them dont have galvanised bases.
For those that dont know they are all steel framed.
I have owned 7 of them and I'm sure the insulated ones are much better in regards to condensation.
They usually have an adjustable vent. It pays not to have them completely closed.
Containers are made from all sorts of materials. I have one here that has sides of fibreglass over plywood. The stainless varies too. Some are made from "muffler grade" stainless(doesn't sound good to me) while others are of a known grade. It usually says on the container.
I think the alluminium (aluminum?) ones are the best made.
Generally they are sold because its not economic to repair them. This is not nessassarily because they are rusted. Sometimes its because the linings are delaminating, or the box is good but the refridgeration unit is beyond repair. As someone said, You need to have a look. Get up on top and check those corners, as well as checking underneath.
Six of mine were shifted about 100 meters being dragged by a bulldozer, while still full. I dont think it did any harm, but I did have to dig a lot of dirt from the door ways.