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.

• This is only an observation, but I think they are twice as powerful now. Commented May 26, 2011 at 10:13
• @The yes notch doubled their power in 1.6. Commented May 28, 2011 at 15:43

3 Answers

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.

• Will 2 rails at the bottom power you for 12? Commented May 26, 2011 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. Commented May 26, 2011 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? Commented Jun 21, 2011 at 19:48
• @Cyclops They increase the momentum to max+a little, instead of max+a lot. Commented Jun 22, 2011 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. Commented Jun 22, 2011 at 12:57

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.

• 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). Commented May 2, 2011 at 21:37
• @Kevin Thx for verification. Commented May 10, 2011 at 11:54

All sorts of good related information: