http://www.jimmys-adventures.net/hiking-katahdin-knife-edge/

hiking Mount Katahdin, Maine?
I’m thinking of going hiking at mt Katahdin with a friend of mine within the next two weeks and doing the Knife Edge trail. I have done mt washington by myself so i was wondering if that compares at all? And i also wanted to know, for a day hike, what to bring?
I guess it depends on what trail you took up to Mt. Washington. The Knife Edge is a little more like the Lafayette ridge, only narrower in places. We went up the Helon Taylor (AT) which is the longest, but gentlest grade, across the Knife Edge, and down the Saddle to Chimney Pond. The Chimney requires a bit of stretching to get down, and the Beehive requires some scrambling to get over. There is nothing on Mt. Washington this exposed, so no comparison there. The trails are lots and lots of rocks and roots on the Helon Taylor, so that is similar to the Whites.
The Saddle is like coming down a rocky rain gutter. I haven’t done Tuckerman’s Ravine, so not really sure about that.
You definitely need to be camping somewhere in the park the night before, because you need to beat the gate opening at 5:00 or whatnot to get to the trailhead. We camped at Abol, woke up at 3:30 and got to the gate at 4:30/4:45 and drove around to Sandy Stream Campground (I think) to get to the Helon Taylor Trail. Since that campground is usually booked far in advance, you take what you can get in the park! It took 20 minutes to get to the gate from Abol, and 20 more to get around to Sandy Stream.
Therefore, I do not recommend trying this as a day hike unless you are willing to be parked in line to get in the main gate no later than 3:30 am, and the park entrance is 20 miles (lonnng miles) from Millanocket. The rangers won’t give any passes to the popular trail heads once they are full and not all trails go over the knife edge.
I have some cool pictures if you want to see them.
Knife Edge, Mount Katahdin. 2000 foot drop.