HANS vs. ISAAC

bmarchet · 06-06-2005, 11:59 AM

Please send feedback and thoughts.. i am definitely buying one of the two in light of recent events..

1. ISAAC seems scary bc youre tethered to the harness. could the pins fail leaving you unable to exit the car?

2. HANS is too bulky to easily exit car if door doesn't open...

3. Seems like user error, belt slippage, ineffective in lateral crash/impact all negatives of HANS.. . but is ISAAC any better?

Prob a good time for all of us to evaluate safety options... Can/ should a net be used in conjunction with these other devices?

thanks.

911teo · 06-06-2005, 12:14 PM

Try a search of the archives in the racing and autoX forums.

The issue has been covered on rennlist as well...

The way I see it is that I am going to get an ISAAC intermediate.
It seems to me that it is the device that would function better in a non all out race car. The HANS device is certainly fantastic but I feel it needs to be used in conjuction with Hans specific belts, hans seat etc.

There is another alternative, R3. Again on rennlist (http://forums.rennlist.com/ then choose Perf & Comp, then racing then do a search for Isaac) this issues has been covered a lot of time.

I alco came to the conclusion that a roll bar (or at a minimum a harness truss) and racing shells are necessary to improve the passive safety of our cars on the track.

chrisp · 06-06-2005, 01:37 PM

Has point #1 been discussed? I was thinking about this on my drive in to work today. What if the system is under tension and you need to pull the pin. Does it come out easily under load? The only example I can come up with is the car is upside down, your hanging from the belts, the roof is compressed enough that your head is bent over and one of the Isaac units is under tension. There may be many other scenarios but I didn't give it too much more thought.

In this scenario (upside down) you wouldn't want to release your belts and then the Isaac so the Isaac must release under load.

Can the Isaac pin be pulled under load?

Plavan · Plavan's Garage

What scares me about the Isaac is that it is SOOO uncommon that if I were to get in an accident, and say there was a fire.... Would the cornerworker know how to get me out in time???? Yeah, they can cut the belts.... But my helmet is still attached to my belts....Someone seeing the Isaac system for the first time is saying WTF? What the heck is this? I said the same thing. I'll stick with a Hans.
(I'm not saying the Issac system does not work)

Jack Olsen · 06-06-2005, 03:00 PM

Quote:

Originally posted by bmarchet
1. ISAAC seems scary bc youre tethered to the harness. could the pins fail leaving you unable to exit the car?

If you've seen the pins, you would not be able to think of a way for them to fail. If you were trapped, and they somehow failed, you could always leave by unstrapping your helmet. Corner workers will cut your belts no matter what, so it's not an issue if you're unconscious.

Quote:

Originally posted by bmarchet
2. HANS is too bulky to easily exit car if door doesn't open...

This is true. But it's not a deal breaker, IMO.

Quote:

Originally posted by bmarchet
3. Seems like user error, belt slippage, ineffective in lateral crash/impact all negatives of HANS.. . but is ISAAC any better?

These are all Hans issues. Isaac's chief benefit is that it's user-proof. In other words, so long as it's on, there are no user comfort adjustments, belt misalignments, belt width issues, seat bolster issues, user size issues, etc., that will diminish its ability to function. The Hans is a great restraint, but I would not be comfortable moving from car to car in one. I've seen too many stories about belts slipping off.

If I had a fully-prepped race car, and it was the only car I was going to ride in, I'd probably get a Hans, and do some practice exits.

Since I instruct, and move from car to car, and tend to get less concerned with safety and more concerned with comfort as time passes, I got an Isaac. As I mentioned in another post, it doesn't punish me for being a lazy idiot.

Quote:

Originally posted by bmarchet
Prob a good time for all of us to evaluate safety options... Can/ should a net be used in conjunction with these other devices?

Side nets: ideally, yes, on both sides.

Both the Hans and the Isaac are great restraints. I'm less impressed by the Hutchens and others. But I'm not an expert. The new Isaac tether system seems like a no-brainer for the occasional DE driver on a budget. It costs about the same as one of my tires.

Quicksilver · 06-06-2005, 03:45 PM

Hutchens Device.

I'm not sure why no one discusses it. You wear it and it doesn't attach to the car in any fashion.

Plavan · Plavan's Garage

I have the D-cell which is similar to the Hutchens device.....With so many straps, you never know if you have it adjusted right and there is some room for error. Its also a pain putting on before a run. You feel like you are putting on a parachute.
Once the new Snell helments come out in October, I plan on getting a new helmet and a HANS. My Cousin, Aunt, and Uncle have the HANS and like it.

FYI- you have to replace the D-cell or Hutchings device every 2 or three years....($300 to $400) With the HANS you just have to buy the $25.00 straps every 2 or three years.

911teo · 06-06-2005, 05:22 PM

Quote:

Originally posted by Plavan
What scares me about the Isaac is that it is SOOO uncommon that if I were to get in an accident, and say there was a fire.... Would the cornerworker know how to get me out in time???? Yeah, they can cut the belts.... But my helmet is still attached to my belts....Someone seeing the Isaac system for the first time is saying WTF? What the heck is this? I said the same thing. I'll stick with a Hans.
(I'm not saying the Issac system does not work)

We have morning meeting between the drivers and the marshalls b4 the track is open to the various sessions. To me that would be the perfect opportunity to make sure that everybody is familiar and comfortable with the device... I'd make sure everybody sees how it is operated and how to "unlock" it.

Plavan · Plavan's Garage

I do not know if you have seen the corner workers out in Pahrump, NV, or Willow Springs or Buttonwillow....

Just kidding
(Watch me get black flagged at all of those 3 tracks now

)
Luckly, we do have some smart corner workers. You gotta love them for standing out there all day while we have fun.

lateapex911 · 05:48 PM

Quote:

Originally posted by Plavan
What scares me about the Isaac is that it is SOOO uncommon that if I were to get in an accident, and say there was a fire.... Would the cornerworker know how to get me out in time???? Yeah, they can cut the belts.... But my helmet is still attached to my belts.....
(I'm not saying the Issac system does not work)

I've worked corners, and held training sessions for cornerworkers on the various H&NRS, and I can tell you, if your car is on fre in a serious way, they cut the straps, and pull you out by your suit loops on your shoulders, whether you like it or not!. (Thats why those loops are there). The Isaac will remain on your helmet, and the belt rollers will slide right off the cut belts like butter.

I have an "Isaac Equipped" sticker right next to my window to warn the workers, and "pull" decals on my helmet with arrows pointing to the pins, which are pull release as well as push pin release.

Because of the nature of the design, this thing only functions in G loads...it's a damper. So it is very unlikely it will be "jammed", but I have tried to "pop the pins" while I tried jamming it, and "poof"..... no problemo.

I'll tell you what, in the event of a fire, I feel a lot better trying to crawl out with an Isaac than I do with that "skyhook" of the HANS....but then I practice bailouts regularly so its one of those automatic responses.

lateapex911 · 06:35 PM

Some various points:

Strap based systems are all subject to stretch, and they will only meet their claimed numbers if adjusted as they were while testing. There may be movement restrictions that the driver is uncomfortable with when they are adjusted tightly enough to be fully effective.

Strap based systems are subject to degredation. Most sanctioning bodies are imposing "term limits" on the straps used in restraint systems of two years, so there will be future expenditures to maintain a system in it's "as new" level of functioning.

Strap based systems are generally not as good laterally, and totally ineffective in reverse impacts, even when the straps are properly located through out the crash event. (HANS has clearly had issues with belt slippage, as they have just modified their design to try to contain the belts better)

I find the Isaac to have better mobility during use, and as Jack points out, there is no way to "mis-adjust" it. It won't "age", so there is no concern over future expenditures to get it back up to spec, nor using it in a less than perfect condition..

In my use I have had to get out when the car was flaming, and it was a no brainer. I've also used it for 3 hours straight in 95 degree ambient, and it actually aided in holding up my tired head in the last half hour!

Both HANS and Isaac are top flight firms. Isaac has it's roots in the biomedical parts world, so they are quite used to the rarified air of engineering in the medical field. Thier upgrade program is phenominal...last year at the SCCA ARRCs (American Road Race of Champions) in Atlanta, an Isaac engineer stuck his head into my car half an hour before my race...I got nervous..."what's he doing?" I thought... Just swapping out some parts...in a minute flat he was done. "Cheaper than shipping it to you!" he joked...I make it a point to not look a gift horse in the mouth! LOL

They also had rental and trial programs where they fed ex you a helmet and system for you to try...I am not sure if they are still doing that, but that seemd like a easy way to try before you buy.

Their new "Link" system would be my choice for a budget restraint. It's a smokin' deal.

To me, I think the Isaac is a great way to go. It only lacks the big name of the HANS (And don't get me started on how the FIA called HANS and asked HANS to write the spec for them! Talk about being in bed! Think there are kickbacks???)

In a formula car, where the egress issues are completely different, and where the head is largely restrained by the head pads on the side, the HANS makes sense. In a sedan, the Isaac makes more sense.

lateapex911 · 06-06-2005, 06:37 PM

Oh...and one last point...You don't have to drill your helmet with the Isaac, (and loose the Snell certification).

Emission · Emission's Garage

Quote:

Originally posted by lateapex911
Oh...and one last point...You don't have to drill your helmet with the Isaac, (and loose the Snell certification).

How is it attached to the helmet then?

Jack Olsen · 06-06-2005, 09:54 PM

You can drill it, or use adhesive. Or both.

Emission · Emission's Garage

Quote:

Originally posted by Jack Olsen
You can drill it, or use adhesive. Or both.

Thanks.

lateapex911 · 06-06-2005, 10:24 PM

here's a pic of my old helmet with the mounts bonded on. The adhesive is some pretty cool aerospace grade stuff.

The mounts have four holes predrilled, so i used a countersink bit to chamfer the top edge, thinking that it would give the adhesive a better bond. Of couse, that's a step thats really just a mental thing..the bond us staggering without any mods.

bmarchet · 06-08-2005, 08:08 AM

thank you everyone... keep feedback coming.

Cory M · 01:06 PM

If you're seriously considering either system you should really check out the thread titled "Tried an Isaac" in the racing section of Rennlist. It's like 13 pages long with several posts by gbaker, the designer of Isaac. I found it extremelly informative especially when Greg Baker joined in at around page 5. All of the questions posed here (and more!) have already been answered by "Mr. Isaac" himself on Rennlist.

EDIT- The post with all of the info from the Isaac designer that I was talking about is actually titled "Tried an Isaac" not "HANS Devices and DE" (though I think he posted on both of them)

Formerly Steve Wilkinson · 06-08-2005, 10:39 AM

Somebody posted that the basic $275 Isaac was "a great deal for the occasional DE'er." That's me, the occasional DE'er, but I just paid the $750 or so for the "real" Isaac, after the advice of friend Steve Weiner, who said that if you're gonna have the accident that makes an Isaac necessary, you don't want to be economizing.

I DE occasionally, and one hopes the accident will be even more occasional.

Stephan

Jack Olsen · 06-08-2005, 10:59 AM

I don't think you made a mistake, Stephan. The 'works in both direction' nature of the regular Isaac means you have a wider range of impact angles protected. The economy model is good for the most frequently fatal (head snapping forward), but would offer less help (in this respect, it's like the Hans) in lateral hits.

None of these devices is designed for lateral hits, but the Isaac with the shocks offers some capability in this respect.