What trains have 'bogie wheels'?

I'd rather not have the couplings attached to the bogies but that purple flatbed thing is adorable... do the one-axled bogies connect to make one middle-bogie or somethin?

[Super]

I thought that you could simply modify any of the easier/cheaper Bogies to remove the couplings. The single axle bogie specially connects each flatbed together to make one pivoting double axle bogie...