Can a OO gauge layout fit a 3 ft table?

The simple answer is yes and no. An OO gauge layout can be made to fit on a 3-foot square table but it is entirely dependent on the radius of the curved segments of the track to be used.

The radius of a curved track section is measured from the centre of a perceived circle to the mid-point of the sleepers (known as the track centre). There are four different options for track radius and these are numbered one to four. The largest segments are the 'third' and 'fourth' radius curved track. Both of these options are too big for a 3-foot square table and so will not fit.

The 'second' radius track will fit but will be tight. Second radius curved track will have an internal curved radius of 438 mm. This means that when placed on a 3-foot square table a layout based on a 'second' radius track will have approximately 5mm from the outside of the track to the edge of the table.

Realistically 'first' radius track will be the only practical option in this case as it will have a comfortable margin of space between the outer edge of the track to the edge of the table. As we can see a 3-foot square table will offer limited options for a conventional layout but could have possibilities to work on smaller-scale scenarios such as a shunting yard.