New Prototype...The "Wreck Knife"

Ed Caffrey

Ed Caffrey

Joined
Jul 23, 1999
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A couple of months ago I had a visit from a local horseman. He was asking if I would be willing to develop a knife to be used primarily for quickly cutting lead ropes, lassos, and similar ropes used to tie or "work" horses and livestock with.

In this part of the world, whenever somebody has an incident with horses or other livestock, it's commonly referred to as a "wreck".

Here are some pics of a couple of Prototypes I finished up today:

WreckKnifePrototype-1.jpg




WreckKnifePrototype1-1.jpg

"Wreck Knife" Prototype #1: 3" blade, with variable serrations for 2/3 of the blade length. Flat ground with convex edge. On this one I decided to leave the point blunt, which I hope will lessen the chances of cutting up a horse if the need arises to cut a saddle girth (strap).
I have to give credit to my wife Cindy....she walked into the shop when I was testing both knives, and I made the statement about having to put handles on them tomorrow. She suggested that I cord wrap them....and I really like it.

WreckKnifePrototype2-1.jpg

"Wreck Knife" Prototype #2: Same blade length (3"), but with a slimmer profile, and sharp point, The biggest difference is the serrations...the are small, with somewhat flatter points, and set up in a 2 small, 1 large configuration.

I've tested them on nylon and cotton "lead" ropes, and both go through cleanly with tension on the ropes....now to turn them over to the individual for more testing, and see which he likes best. The toughest part about this type of knife is getting the serrations "right". I spent the better part of a day, trying different combinations and sizes of serrations before I settled on these two.

On a side note, I stumbled upon a method of etching my name that I really like! Prior to doing any final finishing on the blade, I etched both on the highest setting on my "Personalizer Plus" Holding the etching pad on the stencil for a count of ten, then lifting it for a count of 5. I repeated this for a total of 10 cycles, which "burned" the mark in deeply. I then switched to the "mark" setting on the etcher, and did the same thing for 10 cycles. When I peeled off the stencil, there was a lot of "black" around the mark.....but after a light hand sanding with 600 grit, and a quickly "once over" on a super fine Scotchbrite belt, the marks came out great! Here I've been stumbling around with this etcher for over a year now.....and finally figured out how to make it work the way I want!:D
 
Very nice. Your design is very well thought out. These are very similar to the knives I used to use when sailing. Lots of line (there are only two ropes on a boat, everything else is a line or has a name) on race boats and when things go bad for us ("crash and burn" as we call it) the need comes up to have to cut a line or two. Your serrations look good, but I would try to eliminate the flat points between the grooves. I guess make them closer together so they make a point. I have had knives like that and find that they didn't cut as well for as long as more pointed serrations. Also bread knife type, large shallow serrations work well. Boye knives are very good for this type of work and have some good designs if you might like to check out for inspiration. Although you don't need any help making damn fine knives!

Just my 2 cents
-xander
 
Those look great!

The serrations look perfect! How did you get them so even?
 
Looking good. I like purpose designed knives.
Just a thought: how about a bright colour for the handle so the knive is easelier seen or refound in an energency?
(an orange cord wrap perhaps)
 
Great looking knives Ed!

Thanks for including how you did your makers mark, I just got a personalizer plus and have been experimenting to get the best mark.

How is the cord wrap ended? It looks great. The desert camo somehow looks western on them, very cool.
 
Good looking blades, I personally like #2 the best, but I'm not a horseman. #1 down here would make a great rescue knife for cutting seat belts and such.
 
Those are great! I like #2 better just because it would also serve well for general use.
 
Thanks for the input folks! The cord wrap was a way to get the prototypes done a little quicker....but if I do start making this type of knife, I've thought about offering it with either the cord wrap, or "recycled" rubber scales. I'm going to deliver them tomorrow, and then see what the client thinks of each.

Xander: Good eyes! I cut all the serrations by hand, and intentionally made one set pointed, and left the "flats" on the other one. What I discovered while testing them is that the pointed serrations cut better on synthetic ropes (poly/nylon), and the flat serrations worked better on natural fiber ropes such as cotton/hemp. It might come down to what type of rope the client is trying to cut. :)

In the past I've always avoided building blades with serrations, because cutting serrations by hand is time consuming and can sometimes be difficult to replicate on successive blades. I spent the better part of a day working out different serration patterns on test blades, and found that there is a huge difference in how serrations perform, based on the size/spacing. What I found is that a pattern of one large, two small serrations seems to work best. If these become a "standard", I think I'll try to find a method of repeatability for those serrations.
 
Those look really good, Ed. I have been thinking of making something similar for our mounted SAR people here. The serrations I think could be done with some type of file guide or jig, that clamps the blade into place and has grooves at the proper intervals to get the serrations started with the correct placement. From there is is pretty easy to keep them centered or adjust a little as needed while cutting them to full depth. If you haven't already, you might try a carbide grit rod saw for roughing them in, they are usually availible in hardware stores in the tile section and fit on a hacksaw or coping saw frame. They have very aggresive grit and cut much faster than diamond files, in my experience.
 
Ed,

They look tough as Woodpecker lips!

Mark
 
Ed, that's interesting about the shape of the serrations. It makes perfect sense with what I have found out over the years. We use all synthetic lines like spectra, technora, aramid, and polyester covers. I haven't dealt with much natural fibr stuff since my apprenticeship aboard T.S. Californian, and for emrgencies we had hatchets or the Bosun and I (BM1) had traditional rigging knives with plain edges, and to cut the lines we would grab a belay pin and smack the spine of the knife. Although I don't suspect the horse would be in favor of that method.

On a related side note, I lost my rigging knife to Davey Jones' locker this year. You are the first maker I have seen that does anything similar to what I need. Do you accept customer designs to work from? You can either message me or reach me at fast14riot@gmail.com to keep this thread on topic.


-Xander
 
I like the designs. I used to date a girl who worked for a breeder, breaking haflingers, and she asked me to make her a knife for the same purpose. The design I came up with was a lot like your #1, but with a straight edge. It never left the drawing stage, though, because we broke up before I made it.
Given the type of situation in which you'd be using this knife, I'm curious why you didn't opt for some type of small finger guard to keep your hands off of the edge.

- Chris
 
The blunt point works for me, things are usually happening pretty fast during these wrecks, and I'm the one that usually ends up stabbed.
Chad
 
Great knives, Ed. I'm designing something similar for boating. Do you think a non-serrated edge would also work well on a rope/line cutter?
 
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How did you wrap that handle. to me it looks a little different then what Im used to seeing.
 
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