NATS Animation of transatlantic traffic - and some questions
 

Have a look at this:

How transatlantic traffic looks from space ? video - BT

It's a nice animation of all the traffic across the Atlantic from a busy period during August.

A few questions: what are the rules for separation of aircraft when crossing the Atlantic? It seems from the animation that the tracks are separated laterally by quite some distance. Laterally, do the aircraft have to comply with RNP-10? Presumably the RVSM height separation rules apply? Lastly, do the tracks get moved (North, South, higher or lower) when the Jetstream changes position?

Would be useful to hear from pilots who fly these routes and/or air traffic controllers who manage them. Thanks for your help.

MNPS
 

If you search the internet for MNPS (Minimum Navigation Performance Specification) you will probably find the first suggestion is the website paris icao int, and you can download the 2013 latest edition.
It covers everything about flying across the North Atlantic with sections about lateral separation, RVSM etc.
As for where the tracks are, this is done each day based on where operators want to go and the winds. Operators can submit a form call a PRM with their origin and destination for crossing the Atlantic and once these are all drawn on a chart a decision is made as to where that days tracks will be.
Often there is a gap in the middle and that will be to avoid jetstreams against the flow. I have been to Shanwick a few times and seen the chart they prepare. I even have a copy of one somewhere.

The tracks are one degree apart so in round numbers 60 miles. There is talk about going to half degree separation sometime in the future. It is in effect RNP 12.6 now going to RNP 10 in January of 2015. The tracks are defined in the daily track message and are designed to take advantage of tail winds and minimize headwinds. There are two sets of track each day. One runs from 01z until 08z and is designed for eastbound flights. The other runs from 11:30z until 19z and is set up for westbound flights.

Marker, that's "TMI" for him, gettit?

I'll get my coat!