Train Graphic
Great Western Passengers' Forum
15.12.2019 - what changes?
Great Western Coffee Shop - [home] and [about]
Read about the forum [here].
Register and contribute [here] - it's free.
*** Use the skills of your team - [here]
 today - Network Rail Surgery, BWT
24/12/2019 - No GWR trains, Paddington
25/12/2019 - No GWR trains (at all)
25/12/2019 - No train - Severn Tunnel
25/12/2019 - North Downs - Ash-LGW closed
27/12/2019 - No GWR trains, Paddington
Random Image
Train Running @GWR Twitter Acronyms/Abbreviations Station Comparator Rail news GWR co. site Site Style 1 2 3 4 Chat on off
Next departures • Bristol Temple MeadsBath SpaChippenhamSwindonDidcot ParkwayReadingLondon PaddingtonMelksham
Exeter St DavidsTauntonWestburyTrowbridgeBristol ParkwayCardiff CentralOxfordCheltenham SpaBirmingham New Street
December 16, 2019, 01:55:40 am *
Welcome, Guest. Please login or register.

Login with username, password and session length
Forgotten your username or password? - get a reminder
Most liked recent subjects
[130] Shortage of train crews on Great Western Railway since Septemb...
[118] 15th December 2019 - Santa on the train from Melksham
[90] Our, your,the next station stop is confusing
[56] What's happening on 15th December 2019?
[49] Great Western Main Line electrification - ongoing discussion
[32] Sunday service for Acton Main Line and West Ealing
News: A forum for passengers ... with input from rail professionals welcomed too
 
   Home   Help Search Calendar Login Register  
Pages: [1]
  Print  
Author Topic: Are you sitting comfortably? (and can you quantify that?)  (Read 624 times)
stuving
Transport Scholar
Hero Member
******
Posts: 4310


View Profile
« on: August 14, 2019, 01:03:56 pm »

Last year RSSB started a study into seat comfort (done by Arup and FIRA). Well, actually they started back in 2016 with a literature search that showed there wasn't any accepted way of specifying the relevant factors of seat design, and after asking around started project T1140 to create a measurement method. T1140 is called "Defining the requirements of a seat comfort selection process", but don't worry - it's not quite that abstract: it is about the form of requirements used in choosing seats, not about the requirements the selection process must meet (though they did that, at the start).

Finding the right report is tricky, as there are several, each with its own web page,  but this is the final report on SPARK.* I imagine the bated breath is all for use on the matter of squidginess (not their term), and this is the relevant section:

Quote
Seat pad requirements summary

The compressible seat pad is an important factor when considering seat comfort. Paul Branton’s seminal report1 on seating behaviour, body mechanics and discomfort found that:

  • Based on 104 subjects, approximately 50% of the body weight is supported by 8% of the seat area (under the ischial tuberosities).
  • ‘The seat pan carries 65% of the user’s total weight’. This implies the seat cushion is an important factor in the offset of discomfort.
  • To further understand and define a workable minimum seat pad requirement, the Arup team met with a train seat foam manufacturing specialist and consulted with FIRA’s technical specialist on flammability and physical upholstery testing.

They concluded that recently, there has been a trend towards thinner seat pads (driven by fire, smoke and toxicity reduction requirements and the ever-reducing seat pitch needed to increase seat density and passenger capacity) but this has been at the expense of comfort. This is because most seats have a hard-backed seat structure to support the seated passenger and compressible seat pad. It therefore makes sense that a thicker seat pad can be softer or more compressive before it bottoms out. There is a balance however as a pad that is too thick will affect the seat height and angle and potentially cause discomfort under dynamic conditions. Seats with no hard backing structure and a flexible sling could result in a comfortable, compressible seat pad and a thinner pad thickness. There is potential for innovation in the design of thinner seat pads that achieve the minimum compression requirements.

1 Seating Behaviour, Body Mechanics and Discomfort, Medical Research Council, London, England. P. Branton, 1969.

So next time you are asked  "do my ischial tuberositie look big in this" you'll know how (or whether) to reply...

In the interim report, this was suggested as a follow-up task:
Quote
Use the results of project T1140 to inform DfT on the effect that high train capacity requirements are having on comfort? The benefit would be the DfT relax their focus on fitting in as many seats as possible and enable TOCs to produce trains with adequate space between seats (side by side and legroom) and therefore achieve appropriate comfort levels. 
The final report is less specific.

* Access to SPARK requires free registration.


« Last Edit: August 14, 2019, 07:34:57 pm by Red Squirrel » Logged
CyclingSid
Transport Scholar
Hero Member
******
Posts: 596


Hockley viaduct


View Profile
« Reply #1 on: August 14, 2019, 07:22:58 pm »

How do I know when I have bottomed out?
Logged
stuving
Transport Scholar
Hero Member
******
Posts: 4310


View Profile
« Reply #2 on: August 14, 2019, 08:03:21 pm »

How do I know when I have bottomed out?

That'll be familiar to you, it's like riding a bike on a flat tyre.

My first trip in an IET also involved a 387, and I thought their seats similar. I didn't feel I could squash the pad flat however I sat on it in either, and I could barely do it with my thumb, which of course compresses a far smaller area than any of my ischiadic prominences.

Then I ended up on a 485, where the recent revision of the seating was an angle grinder job and the upholstery is now pretty old. The seat pad is much thicker than on an IET, but I could - with a little bit of bouncing up and down - squash that flat and feel the hard base underneath. I could also do that with my thumb quite easily.

The reports do go into the relationship between pad resistance and thickness, for obvious reasons -a pad that's too soft for its thickness leaves you sitting on a hard shelf.
Logged
Do you have something you would like to add to this thread, or would you like to raise a new question at the Coffee Shop? Please [register] (it is free) if you have not done so before, or login (at the top of this page) if you already have an account - we would love to read what you have to say!

You can find out more about how this forum works [here] - that will link you to a copy of the forum agreement that you can read before you join, and tell you very much more about how we operate. We are an independent forum, provided and run by customers of Great Western Railway, for customers of Great Western Railway and we welcome railway professionals as members too, in either a personal or official capacity. Views expressed in posts are not necessarily the views of the operators of the forum.

As well as posting messages onto existing threads, and starting new subjects, members can communicate with each other through personal messages if they wish. And once members have made a certain number of posts, they will automatically be admitted to the "frequent posters club", where subjects not-for-public-domain are discussed; anything from the occasional rant to meetups we may be having ...

 
Pages: [1]
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.2 | SMF © 2006-2007, Simple Machines LLC Valid XHTML 1.0! Valid CSS!
This forum is provided by a customer of Great Western Railway (formerly First Great Western), and the views expressed are those of the individual posters concerned. Visit www.gwr.com for the official Great Western Railway website. Please contact the administrators of this site if you feel that the content provided by one of our posters contravenes our posting rules (email link). Forum hosted by Well House Consultants

Jump to top of pageJump to Forum Home Page