# What's the maximum number of powered rails in a row that's useful?

I'm going through my rail network, replacing boosters with powered rails. However I'm finding that unlike boosters, which 'break' the laws of minecraft physics (by giving the cart much more momentum than its speed should allow), powered rails can't propel carts over very long distances, and it seems that even making a very long boost doesn't help this.

How should I cluster my powered rails for maximum efficiency? How many should I put at a time, both on flat, and inclined stretches?

### Update

I've un-answered this question and added a bounty to reflect the changes in 1.6.

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This is only an observation, but I think they are twice as powerful now. – The Communist Duck May 26 '11 at 10:13
@The yes notch doubled their power in 1.6. – John the Green May 28 '11 at 15:43

For inclines in 1.6 (tested), one powered rail at the bottom of a slope will boost a cart with a player in it up 6 blocks before needing another boost.

EDIT: TaviRider has made another great video showing all the powered rail things in 1.6.

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Will 2 rails at the bottom power you for 12? – fredley May 26 '11 at 14:37
Have not had chance to test, but since only the speed has been jacked up my assumption is it will take you about 8 or 9. – The Communist Duck May 26 '11 at 14:44
So... Powered rails only increase the minecart's speed, and not total momentum, as the original boosters did? Meaning you can't just do a one-for-one replacement of tracks, but have to go down the entire rail line putting in powered sections? – Cyclops Jun 21 '11 at 19:48
@Cyclops They increase the momentum to max+a little, instead of max+a lot. – The Communist Duck Jun 22 '11 at 7:59
@Communist Duck, I'm not sure what you mean by "max+a little" - carts used to have a really high momentum. I had a 12-track booster that would drive a cart around a fairly large circle (including uphill), and when I replaced it with 10 Powered tracks, the cart didn't get up the first hill. – Cyclops Jun 22 '11 at 12:57

All sorts of good related information:

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"who disturbs our meditation, as a pebble disturbs the stillness of the pond?" youtube.com/watch?v=Z8VD4JXUozM – Jeff Atwood May 3 '11 at 2:58
a word of warning, the answer to this is most likely changing with 1.6, as per notch.tumblr.com/post/5775170768/the-changelist-for-1-6. – Raven Dreamer May 24 '11 at 4:01
@Raven My cursor is poised over the bounty button for when that happens... – fredley May 24 '11 at 9:48
@Raven Dreamer - powered rails increased by 12% – EdGruberman May 27 '11 at 15:02

To boost the cart speed from zero to maximum, you need 4 powered rails in sequence.

To maintain maximum speed you need one powered rail each 26 blocks (25 blocks of rail, 1 block of powered rail).

To maintain maximum speed on slopes, you need to power each second block on the slope.

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I tested powered rails on slopes in this answer and found a powered rail every other track works fine (more specifically, every third is not enough). – Kevin Yap May 2 '11 at 21:37
@Kevin Thx for verification. – Let_Me_Be May 10 '11 at 11:54