What happens when you issue shutdown force is as the thread on GARYM's posting explains, by SHUTDOWN ABORT and then performs a startup.

To be on the safer side, try doing the following,

set ORACLE_SID
svrmgrl
connect internal
shutdown immediate
startup

This wouldn't require any recovery, when you start, other wise you have to perform some recovery to bring back things in sync.

To connect through the sqlplus, try
set ORACLE_SID=
sqlplus connect / AS SYSDBA


Sam

Sam