Every hour 24/7 from Oslo bussterminal to Kongsberg(80km)Ntodden and back.
The Purple busses are named Timeekspressen and its line 1. They also connect with airport express busses from Oslo Airport Gardermoen.(135km)
Apart from that you can use the train from oslo or Gardermoen directly to Kongsberg every hour in day/evening/early morning.
Torp airport (Sandefjord)
As some of you already know Torp is not close to Oslo but 113km and 1,5hr of driving to the south west.
To get from Torp to Kongsberg there are some options.
Train: You will have to take the train to Drammen and connect to Kongsberg there.
There are no trains on the airport. You will have to take taxi or bus to nearest trainstation.
Taxi: Kongsberg taxi +4706070 can give you a fixed price on the trip. If lucky you can split the price with somebody else.
Ktt: Taxi company driving business men to and from the airport. Call them a day or two before you arrive and they can tell you if they have a transport at the time you need.+4732286490.
A cartrip takes 65-75minutes from Torp to Kongsberg
Landed at Oslo airport,very efficient.Came out of arrivals bought a train ticket from the booth,walked over to escalator,went down,got on train.That easy...Trains ran perfectly on time lots of space for skis and luggage.
No language barrier, as they all spoke better English than me !!!!