Raised bed made from sleepers.

[mtr1]

OK as per title I'm making a raised bed from sleepers, it will be about 1500 wide by 11m long and 3ft high. The back will be the old concrete and cross link fence, what I would like to know is about drainage, do I need any? I will be offline for a while as my laptop needs a new hard drive, so might not get access to the internet to answer any questions. But will try on my phone TIA.
Ps. Do I need any special soil? Or will topsoil from another area in my garden do?

[weejohnny]

http://landscaping.about.com/od/landsca ... eds_10.htm

[mtr1]

Thank you, very handy link.