8 replies to this topic

[Dexstar14]

I am a first year Engineering student at the University of Saskatchewan. I am in a design class where we have chosen to do a project on upgrading the Chairlifts to accomodate snowboarders rides up the hill more comfortable. We need to know the design constraints that are used in a typical chairlift design (Weight limits of the cables used, how much load the towers can handle etc.). The proposed project must be a retrofit to chairlifts that are already in commission. If you could give us any information in regards to the constraints taken into consideration when the chairlifts are designed that would greatly be appreciated.

If you could give us information on:
-Weights of the chairs (2,3,4, 6, 8 person sizes)
-Materials used for frame of chair
-Sizes and tensile strengths of the cables used
-Strengths of the towers
-Weight constraints on the chairs themselves

Again any information that you could give us would be greatly appreciated.

Thanks

This post has been edited by Dexstar14: 07 February 2008 - 07:21 PM

[aug]

Dexstar14, on Feb 7 2008, 08:18 PM, said:

I am a first year Engineering student at the University of Saskatchewan. I am in a design class where we have chosen to do a project on upgrading the Chairlifts to accomodate snowboarders rides up the hill more comfortable. We need to know the design constraints that are used in a typical chairlift design (Weight limits of the cables used, how much load the towers can handle etc.). The proposed project must be a retrofit to chairlifts that are already in commission. If you could give us any information in regards to the constraints taken into consideration when the chairlifts are designed that would greatly be appreciated.

If you could give us information on:
-Weights of the chairs (2,3,4, 6, 8 person sizes)
-Materials used for frame of chair
-Sizes and tensile strengths of the cables used
-Strengths of the towers
-Weight constraints on the chairs themselves

Again any information that you could give us would be greatly appreciated.

Thanks

most of the info you are asking for is in ANSIb77 code book,


Weights of the chairs (2,3,4, 6, 8 person sizes)different manf. different weights

Materials used for frame of chair; mostly galvanized steel tube. and different manf. use different dimension materials

Sizes and tensile strengths of the cables used; figure a 5:1 safety factor

Strengths of the towers; this depends on the location of the lift ie wind ,snow and profile

Weight constraints on the chairs themselves; design a chair and build your lift around the carrier with dimension and weight figured into the overall design of the chairlift.

note: we are not here to do your home work for you, there are many design considerations to be taken into account. the ansi code book will give you the guidelines and common practices used in chair lift design. please look at a copy of this and then ask questions.

[Dexstar14]

Thanks alot, the code book should really help, i have been trying to find something like it and have come up with nothing, but now that i know what its called i should be able to find something.

[Lift Dinosaur]

It is actually a STANDARD book, not a CODE book. Current version is American National Standard Institute (ANSI) B77.1-2006.

Dino

[aug]

dino , thanks for the correction

[Dexstar14]

Ok guys i spent all day looking for this book and i know what I am looking for its the ANSI b77.1, my university library doesn't have it and i can't afford the pricetag on that bad boy bein a student. So to be honest i don't know what to do. We are supposed to get an experts opinion in this whole design project so would you say that adding say maybe 10lbs per chair would be a safe addition to the lift as a whole. From what i have found the lifts are tested by placing boxes with garbage bags in them and filling them with water to simulate people on the lifts. The tests consist of regular upihill usage, braking and reversing of the chairs. Also from my research i have discovered that when designing chairlifts the mass of the average person is considered to be approximatly 75 kg. (this is all what i have found on the internet so please correct me if I am wrong.) If you could give me your opinion on this i would really appreciate it .

[aug]

I know Canada has a standards /code book also . Maybe you can find this publication . Can any of the techs above the 49th parallel help this student with the published name of this standard.......

[Lift Dinosaur]

The Canadian version is CAN/CSA-Z98-01 from the Canadian Standards Association.
I don't consider myself an "expert", but I can give you my "opinion".
ANSI B77.1 -2006
Sec. 3.1.1.1 (3. is detachable lifts) and 4.1.1.1 (4. is fixed grip lifts) specifies design passenger weight as 170 pounds (77.1 kilograms).
Sec. 3.1.1.11.2 states that the Acceptance Test will be conducted with 110% of design live load.
An average detachable quad chair and hanger weighs about 215 kgs with the grip about 60 kgs. An average fixed grip quad chair and hanger weighs about 130 kgs with the grip about 14 kgs.
I don't have any specs on a double chair, but I don't think adding 10 pounds (4.5kg) would affect the design of a modern day ski lift (while there are still plenty of double fixed grips running, there aren't too many "new" ones built).
I hope this helps you.

Dino

[LiftTech]

Lift Dinosaur, on Feb 8 2008, 11:41 AM, said:

It is actually a STANDARD book, not a CODE book. Current version is American National Standard Institute (ANSI) B77.1-2006.

Dino

It’s only a standard until your authority having jurisdiction has adopted it, then its code, law or whatever you wish to call it, you still must follow it.