There are a limited number of trains operating to various destinations from Chennai Beach, according to Railway information available at stations. Based on this, I have got the following table ready. It may be a useful thing for those who plan to connect to these places from the Beach – Tambaram and the Velachery – Beach MRTS lines. The alternative for travel to Arakkonam and Gummidipoondi is to alight at Park or Park Town (MRTS) and walk to Chennai Central where there are more frequent services.
I must add the caveat that this time-table is dated now, and it would be good to check with the official schedule.