Chart Query
 

Why on this SID chart (DVR6J from 09R at LHR) is it necessary to state an altitude restriction of "At 6,000" at 5d before DET, when an identical altitude restriction on this SID already exists at 16d before DET?
The departure is already capped at 6,000ft, so it seems a bit pointless as you can't climb again until cleared anyway. Same applies for the departure from the 27's (visible also on this image on the easterly track into DET) which has the 6,000ft restriction repeated at 29d and 5d.
Is it just to make doubly sure that pilots won't continue to climb above 6,000?
http://img210.imageshack.us/img210/6144/dvr6j2wh.gif

Not sure why it is on there more than once, but those are minimum altitudes, not maximums. (I'm pretty sure) I've never read international charts like that. Don't really know why they would put a maximum altitude if its a SID.

Probably due to the number of level busts previously in the London TMA. The 6000 ft and not FL 60 constraint is emphasised on all departures from the London airports. Equally if it is a 5000ft constraint it is emphasied.

FL050... they are ACTUAL levels to be at, as it clearly states, not maximum or minimum.

Any definitive answer then? Is it just a reminder to help prevent level busts?

Can it be to show that you have to be at 6000' at d16 and have to stay at 6000' till d5?

But you have to maintain 6,000ft on reaching anyway as this is a condition of the SID. You would only be able to climb above this level if cleared by ATC.

Do you have a picture of the whole SID?

I would suggest it is to deconflict with other SIDS? I.E. maintain 6000' UNTIL 5 before as other traffic will be above? Where is the cap of 6000' on the chart?

It is my educated guess that the 6000ft restriction at DET DME 5 is for RTF fail purposes, to ensure that an aircraft experiencing RTF failure does not climb to FPL level before this point, to ensure separation from conflicting routes.

Thanks ATCO Two, hadn't thought of that scenario.

The conflicting SID is the DVR departure from EGSS at FL70 or (min.stack).