Cost analysis

Costing something like this is a bit of a black art, and I'm not convinced I've gotten sensible numbers out of this process.

I think that I've either overpriced this horribly at ~£150 or I have dramatically underestimated the manufacturing costs, I'm not sure which.

Speccing Electrical Components

Relaxing the packaging constraints has made it possible to reduce costs by using standard electrical components. The most significant of these are the motor and the batteries.

The benefits to using these standard components are measured in cost, both in manufacture and in the design phase. It also happens to reduce the number of calculations and ensure that a reliable, fully functioning product comes out the other end.

Both of these components have been sourced from an RC hobbyist website that lists extensive specifications for each component as well as the type of vehicle they would be used on. The information is there for you to make an educated choice as to which would best suit your application, ideal for this project.

Unfortunately it was not possible to calculate the speed of the motor and hence the prop specifications and power consumption without building and testing a fully working model - a process I simply did not have the time or budget to follow through with during this project.

Packaging Improvements

The radical redesign has allowed for much improved packaging within the Lifeline itself.

These images illustrate the difference:

The top image was the first design. It was entirely limited by the need to pack in as much line as possible. IT relied on miniaturised technology, super capacitors and custom built motors to function. It was not a good design.

The Mk2 version at the bottom is far superior. There is ample room for the torpedo, enough line to create a 50M radar cross section, as well as space to fit a conventionally sized PLB plus batteries for the LED signal light.

The design is far simpler and does not rely on integrating and optimising components to the very cutting edge of materials technology to function.

Switching to a RADAR Detection System

After some more thought on the idea of generating a large RADAR cross section rather than a visual target I have come to the conclusion that it is a no- brainer. The shift fixes the majority of the problems I had with he visual line and generally increase the overall workability of the concept.

Here are some key improvements:

- All S&R helicopters make use of radar, as do most fishing boats

- The radar cross section does not have to be as big, 50M diameter across would be more than enough.

- This radically decreases the amount of line that is needed to be fitted inside as well as  the length of time the torpedo has to travel for.

- RADAR allows the area to be found rapidly and from a great distance

- The search party can track the PLB as well as the radar signal  to home in on the MOB. They can then pinpoint them precisely using the built in signalling tools.

- Metallised line is incredibly simple to manufacture, just mix in a metallic filler compound to the plastic. The is no new technology to research, develop, and invest in.

This is the ideal discovery, it does fix a lot of the holes I was poking in the product and does it all very neatly too!

RADAR!

After a lot of abstractly thinking about searches over sea I got to thinking about how radar works. It turns out that radar is essentially radio waves emitted with a measured response that is a reflection.

Now, what else reflects EM waves? Faraday cages! You can see a Faraday cage in action on the door of your microwave, the mesh is tuned to the wavelength of radiation to prevent it passing through and harming you.

My reasoning is that, a spiral of metal should not be that far removed from a grid of metal. If a grid can interfere then so must a spiral, especially when the wavelengths used range from 1-10m.

Some inspired searching later I've managed to find a paper that studies the possibility of searching for an infinitesimal metal wire using radar which would suggest that it is entirely possible for a metallised line to create a radar cross section.(http://proceedings.spiedigitallibrary.org/proceeding.aspx?articleid=1338286)

Torpedos

With the changes made to lifeline it is clear that the outer casing containing signalling lights, reflectors and transponder will have to stay with the MOB.

In this case it is simply a launcher tube for a torpedo.

This improves things dramatically from a standard components perspective as we can now place a motor, gearbox and battery from an RC boat inside a casing and ultrasonically weld it shut. This will allow us to meet IP67 rating at very low cost using quality components. The trade-off here is with cooling but it should be possible to use water cooling or completely ignore it as the motor will be running for such a short period.

Re-Think

As I said before, Lifelife currently makes no sense as a product.
The main problem just now is that sending all of your assets away on a string is a bit pointless.

It all needs to be considered from the usefulness to the person in the water. For example, the PLB will need a separate battery as before in order to stay functional even if the other battery is flat.

If the light is staying with the user but the line is still travelling then we need another separate battery from the LED lighting.

So in all we have 3 electrical  systems in one product. This should not be a problem, they should even be able to charge and be switched on my the same systems. The added complexity is worth the value added to the product. The system will look something like this on a high level visualisation:

My next big issue is that I don;t know who to rectify the line visibility problem. None of the solutions such as dyes and luminous coatings can't last long enough to be worthwhile and you are unlikely to see them in the day still anyway. It needs to be passive but non bulky....

Pre Submission Presentation

I've come to the conclusion whilst doing these sheets that this product needs a major re-think. I'm not sure what that will entail yet but it's mainly focussing on the internals and the fact that at present the thing flies away with all of your signalling capability. Not a good move. I'm also still not sold on the luminous line but haven't found an alternative yet.

Presentation pages ready for pre sub pres' tomorrow. I got some good renders and photoshop in context shots so I think this should be quite good. My main concern is that aside from the first page and technical features they are quite wordy sheets. 

Pointless Features

I'm beginning to notice some fatal flaws in the Lifeline, mainly to do with the glowing line concept.

Imagine you're flying over the sea at night, searching in vain for a head bobbing between the waves. Suddenly a glow appears on the horizon, as you get closer your realise that a spirla of light is leading you right to the MOB. He has been rescued at least half an hour before the search pattern was set to get there, half an hour that would have been 20 minutes too long.

Now picture that same scene but during the day. Hanging out oft he helicopter in vain, following the search pattern. Half an hour later you fly over the spot where he was and continue along the planned route with a heavy heart.

Unless it is night-time this product is essentially useless. How can I get round this and solve the problem?

On the bright side I'm putting some usb ports in the charging hub that will ensure an opportunity for the crew to charge any devices they have on board from a single outlet, freeing up limited resources within the boat.

3d graphene has also just been invented in the lab(http://www.nims.go.jp/mana/research/highlight/vol9.html). Tensile strength exceeding 1TPa - that would be an interesting material to use! Unfortunately it cannot currently be mass produced.

Material Decisions

I am using Cambridge Engineering Selector to help me specify materials for this project. With the user, environmental and manufacturing requirements in mind it is very simple to narrow down material choices.

I have decided to use poly-amide for the casings of Lifeline as it has mechanical properties favourable to the maritime environment. Most noticeable is the high resistance to environmental stress cracking, impact properties at low temperatures, price, and translucency.

It is also well suited to mass production processes such as injection moulding - essential for this product.

Another material that I have come across is graphene, also known as super capacitors. They are able to charge in seconds and discharging over much longer times. This could be an answer to the energy storage problems and would also reduce the chore of charging - improving uptake or at least encouraging regular use.

Project Icehands

Live fire testing of the grip models was performed earlier. OUCH!

 I filled a basin with cold tap water and then chucked a bag of ice in and left it to cool down for five minutes.
Experimental procedure was to hol my hand underwater for as long as I could take then try the different grips with a quick 30 second dunk to cool my hand back down after being out of the water.

I can honestly say I was not expecting it to hurt as much as it did. I lasted about 3 minutes before I was jumping up and down trying to keep going.

Round Grip: 40mm

 Hexagonal Grip: 25mm

 Hexagonal Grip: 38mm (WINNER)

 Pentagonal Grip: 38mm

Hexagonal Grip: 47mm

It was shocking how quickly my grip strength faded, I could not put any pressure on these grips at all (you can see it in the pictures). Having said that, there was definitely a sweet spot for a good sized grip.

The round grip was ideal for sitting in your hand but felt really insecure as it spun round farily easily. However, the hexagonal grip of a similar size retained the ideal holding dimensions whilst the corners provided a secure feeling.

The 40mm round grip and 38mm hexagonal grip were the best received through my previous survey which cemented the decision to go with the hexagonal form factor.

Aftermath: Tutorial 3

Unfortunately our tutor wasn't able to make this group session, surprisingly it turned out to be very productive anyway!

No one seemed too keen on the ice water testing route but did appreciate the idea. I think I'm going to be putting this off for a bit, might take the plunge tonight...

Issues highlighted by this tutorial were to do with material selection and tech integration.
Materials wise I haven't given this proper thought yet. I want to use an engineering plastic such as polycarb or polyamide but I haven't had a look at CES yet to decide properly.

The integration of coastguard contacting when the device is trigger is trivial. Personal locator beacons currently exist that transmit a distress signal to a satellite and this is monitored worldwide. They are relatively inexpensive and will integrate nicely with Lifeline.

Sketch Modelling

got some foam modelling in the workshop done today. I wanted to test out the different possible shapes for the handle of Lifeline. 

Based on the optimum power grip diameter of 1''-2'' I cut out 3 different sizes of foam hexagon which I will be testing using ice and cold water later on alongside a handy baseball bat as a round grip and also some steel tubing taped together as an ovalised tube.

I will also be handing these out to people with varying sized hands over the next few days and asking them to pick the one that feels best. The idea is that if their responses converge on a similar size and I agree with that after freezing my hand and trying them again then I will have found something close to good for the average person. 

I won't be asking anyone to participate with the ice water experiment because I'm pretty confident it'll hurt.

How Are Searches Conducted?

There are whole textbooks written on the science of searching for people, many feature lengthy calculations and derivations but it is true that the most commonly used search patterns used at sea are these three:

These three search patterns are extremely effective when carried out by a party such as the coast guard or the navy, in other words people who have training . We get into problems when boats and crews who are inexperienced or out of practice try to search. Inevitably their patterns will start to drift or their track distance is too large and so on. For this reason the coast guard will generally refuse all offers to help with a search until the situation becomes desperate. The lifeline is clearly going to have to cater to both professional searches as well as those conducted by untrained amateurs. The difference between the two has cost lives in the past. 

My next research session is going to have to begin looking into visibility at sea - how far can you see from a boat? What can the human eye discern at distance? But first, I'm going to go do some sketch modelling.

Simulation Dead end

Modelling for both people in the water and the power requirements of the lifeline ahve hit a dead end.

Firstly, there are so many variables in the first case that it doesn't help much more to have various parameters that are editable because it is never going to be accurate. I am going to use the chart I posted previously as a guide to aim for:

I've decided that my best option is to ensure that Lifeline is operable within a couple of minutes and that it's ergonomics and geometry are well suited to the conditions and the physiological effects they cause.

The other model, of Lifeline's electrical power requirements has also died a death. I have calculated the power requirements for a certain speed, but I do not know enough about prop geometry (I also haven't been unable to find clear information online) to be able to then translate this into a motor speed and hence current drawn which would allow me to spec a battery.

I've sunk a fair bit of time into it so I'm going to call it quits there and spec the motor and battery by comparing with RC models that deal with comparable loads.


A more successful foray into excel allowed me to calculate the space required for a set amount of line. It turns out spirals take a huge length to create relatively small diameters. I used an online tool (http://deepfriedneon.com/tesla_f_calcspiral.html) to calculate the length of line for a given diameter and then used excel to calculate what volume I would need to fit this in.

Aftermath: Tutorial 2

On Friday we had a group tutorial with Craig Lynn, he was really helpful for everyone and I came away with a huge list of things to get working on!

A lot of what came up in the tutorial I had already been working on but there were definitely some interesting ideas brought up.

The thought of using a propulsion system that was not electrically based had not occurred to me so I'm going to do a bit of digging. Compressed air looks like it might work although I'm not convinced that the numbers work so far.

Defining the problem

The start of any project is working out what the problems are that need solving.

Currently, the main ones seem to be:

What is the limit on size? It has to be small to be carried about but it also has to be large enough to contain the features that make it useful.

The line! What is it made of? How is it visible? How much do we need? How fast does it need to deploy?

Finding People: If no one reports the MOB, no one will be looking. How do we alert the appropriate authorities? (Thinking AIS PLB)

How do you keep it charged? It's only useful if it's charged so how do you make sure it gets charged without making that a pain point for the user? Especially on a boat with limited power availability.

Hmmm...

Duncan Yatch Chandler's Visit

We hopped on the subway and had a mosey about in the shop. We got a good look at various styles of life jackets and some wet weather gear but in all honesty it was pretty much a wasted effort.

As hey are catering towards yatchs and the casual sailor type there wasn't much of use for our project. We asked a few questions but the guy couldn't answer most of them. We were hoping he would have a contact or two to chase up but that was a no go as well.

Worth a try!

Concept development

I've decided on concept three, the trailing line. I feel that is a product that would benefit more people, after all MOB's affect every boat whereas not every boat is putting down crab pots for buoys to attach to.

It also turns out that crab pots are put down over a huge area, having your nearest safety buoy 60 miles away is not going to help much.

My next step is to develop some models on excel of someone falling into water to gauge the windows of opportunity to act, how fast you might need to swim etc etc.

Carwyn and I are going to Duncan Yatch Chandler's on West St tomorrow morning to get a look at some marine specific clothing and hardware.

Aftermath: Tutorial 1

The tutorial today was a good opportunity to see everyone else's take on the project, some really creative ideas. I especially liked Rob's javelin floatation device - he took something clearly flawed and has put a really interesting spin on it.

This is my buddy feedback sheet from the tutorial. Concepts two and three were most popular although there was most interest in the trailing line concept which I think I will take forward.

I'm not 100% convinced it is the best concept for this project so I am going to develop both concurrently until I have made up my mind. It might be slightly more work/slower but it will put me in a better posiiton if i decide to change tack towards the end of next week.

Three Initial Concepts

These are my three concepts for presentation at the tutorial tomorrow. They are all based on research and insights that I think are reasonable. They all obviously need a lot of work but that is the design process, right?!

Currently, I am leaning towards concepts 2 & 3 though I'm not sure either are viable at present. I'll see what people think tomorrow.

Ideation

I've been digging through a lot of info that has generated a lot of hand written pages of notes and scribbles. Using the post it notes synthesis method that Brian taught has has been amazingly helpful in distilling this information down into core concepts, insights and objectives.

My most important insight is that many boats appear to have a lax safety culture in that they just don't care at all. Considering the fact that a fisherman could move between ships of various sizes, owners and saety records, how are they going to keep themselves safe?

The direction of my initial concept generation has been skewed towards protecting people once any existing systems have failed. I.e. they are in the water and possibly haven't been spotted going over.  No system is 100% perfect.

I am also attempting to think past the obvious ideas towards something a bit more obscure as I think there is going to be a fair bit of overlap between people's three concepts at the tutorial.

Research Update

I'm getting through a lot of websites and general reading online, the fishing industry is packed with jargon that is making it difficult to find/decipher the specifics of different boat types. I am starting to think that it probably isn't that relevant as they will all still be subject to the four core problems outlined by the brief.

I need to get my three concepts together soon so I'll be synthesising all of this data over the next four days and trying to generate some concepts from what comes out of that!

I've managed to find a few well written articles about extremely lucky people. The best (http://www.nytimes.com/2014/01/05/magazine/a-speck-in-the-sea.html) is the story of John Aldrigde fell off his three man boat during the night. He managed to survive through a few clever tricks that could possibly be adapted towards a survival product.

Analysis of the Brief

The brief specifies four common scenarios in which fishermen are most at risk which I can use to help direct my research. The main areas for further research seem to be:

- Culture of the fishing industry

- How boats differ between different types of fishing

- Conditions on board

- Existing safety related products

- Do these get used or even bought?

- How do people cope in water?

- What are the conditions in water?

- Are there any useful survival type first hand accounts available?

Fictional Inspiration - Churchill

Googling 'man overboard' seemed like the best way to start my research. I found this short story by Winston Churchill (no relation) that, though chilling, is surprisingly inspirational. 

Man Overboard

by

Winston Churchill

It was a little after half-past nine when the man fell overboard. The mail steamer was hurrying through the Red Sea in the hope of making up the time which the currents of the Indian Ocean had stolen. The night was clear, though the moon was hidden behind butts. The warm air was laden with moisture. The still surface of the waters was only broken by the movement of the great ship, from whose quarter the long, slanting undulations struck out like the feathers from an arrow shaft, and in whose wake the froth and air bubbles churned up by the propeller trailed in a narrowing line to the darkness of the horizon. There was a concert on board. All the passengers were glad to break the monotony of the voyage and gathered around the piano in the companion-house. The decks were deserted. The man had been listening to the music and joining in the songs, but the room was hot and he came out to smoke a cigarette and enjoy a breath of the wind which the speedy passage of the liner created. It was the only wind in the Red Sea that night. The accommodation-ladder had not been unshipped since leaving Aden and the man walked out on to the platform, as on to a balcony. He leaned his back against the rail and blew a puff of smoke into the air reflectively. The piano struck up a lively tune and a voice began to sing the first verse of "The Rowdy Dowdy Boys." The measured pulsations of the screw were a subdued but additional accompaniment. The man knew the song, it had been the rage at all the music halls when he had started for India seven years before. It reminded him of the brilliant and busy streets he had not seen for so long, but was soon to see again. He was just going to join in the chorus when the railing, which had been insecurely fastened, gave way suddenly with a snap and he fell backwards into the warm water of the sea amid a great splash. For a moment he was physically too much astonished to think. Then he realized he must shout. He began to do this even before he rose to the surface. He achieved a hoarse, inarticulate, half-choked scream. A startled brain suggested the word, "Help!" and he bawled this out lustily and with frantic effort six or seven times without stopping. Then he listened. "Hi! hi! clear the way For the Rowdy Dowdy Boys." The chorus floated back to him across the smooth water for the ship had already completely passed by. And as he heard the music, a long stab of terror drove through his heart. The possibility that he would not be picked up dawned for the first time on his consciousness. The chorus started again: "Then--I--say--boys, Who's for a jolly spree? Rum--tum--tiddley--um, Who'll have a drink with me?" "Help! Help! Help!" shrieked the man, now in desperate fear. "Fond of a glass now and then, Fond of a row or noise; Hi! hi! clear the way For the Rowdy Dowdy Boys!"

The last words drawled out fainter and fainter. The vessel was steaming fast. The beginning of the second verse was confused and broken by the ever-growing distance. The dark outline of the great hull was getting blurred. The stern light dwindled. Then he set out to swim after it with furious energy, pausing every dozen strokes to shout long wild shouts. The disturbed waters of the sea began to settle again to their rest and widening undulations became ripples. The aerated confusion of the screw fizzed itself upwards and out. The noise of motion and the sounds of life and music died away. The liner was but a single fading light on the blackness of the waters and a dark shadow against the paler sky. At length full realization came to the man and he stopped swimming. He was alone -- abandoned. With the understanding the brain reeled. He began again to swim, only now instead of shouting he prayed -- mad, incoherent prayers, the words stumbling into one another. Suddenly a distant light seemed to flicker and brighten. A surge of joy and hope rushed through his mind. They were going to stop -- to turn the ship and come back. And with the hope came gratitude. His prayer was answered. Broken words of thanksgiving rose to his lips. He stopped and stared after the light -- his soul in his eyes. As he watched it, it grew gradually but steadily smaller. Then the man knew that his fate was certain. Despair succeeded hope; gratitude gave place to curses. Beating the water with his arms, he raved impotently. Foul oaths burst from him, as broken as his prayers -- and as unheeded. The fit of passion passed, hurried by increasing fatigue. He became silent -- silent as was the sea, for even the ripples were subsiding into the glassy smoothness of the surface. He swam on mechanically along the track of the ship, sobbing quietly to himself in the misery of fear. And the stern light became a tiny speck, yellower but scarcely bigger than some of the stars, which here and there shone between my butts. Nearly twenty minutes passed and the man's fatigue began to change to exhaustion. The overpowering sense of the inevitable pressed upon him. With the weariness came a strange comfort -- he need not swim all the long way to Suez. There was another course. He would die. He would resign his existence since he was thus abandoned. He threw up his hands impulsively and sank. Down, down he went through the warm water. The physical death took hold of him and he began to drown. The pain of that savage grip recalled his anger. He fought with it furiously. Striking out with arms and legs he sought to get back to the air. It was a hard struggle, but he escaped victorious and gasping to the surface. Despair awaited him. Feebly splashing with his hands, he moaned in bitter misery: "I can't -- I must. O God! Let me die." The moon, then in her third quarter, pushed out from behind the concealing butts and shed a pale, soft glitter upon the sea. Upright in the water, fifty yards away, was a black triangular object. It was a fin. It approached him slowly. His last appeal had been heard.

Decision On The Brief

After some thought I have decided to develop a solution for the commercial fishing brief:

I sat down and did some more in research into the three and concluded that commercial fishing provided the most opportunity for novel design.

The Dakar brief seems too easily solved with GPS tracking and rule changes within the event (severe time penalties for violations).

Passive smoking does not appear to be as big a problem as it is made out to be and could be solved by better education of the risks and the time factor associated with these risks.

Commercial fishing is an industry that operates in the harshest conditions, often with little in the way of safety or insurance measures in place whilst perilously close to the limits of human endurance. This environment should be a challenge to design for considering the number of variables at work.

SCOTSMAN2 Project Introduction

H, I am currently a student at the Glasgow School of Art. One of the requirements for a current project is to blog progress on at least a weekly basis.

This is phase two of a project known as Scotsman in which we have researched and written design briefs. We are now to choose a brief and develop a solution to the problem.

There are eight to choose from and I am still undecided. My short list includes projects relating to;

- Preventing archaeological damage caused by the Dakar Rally
- Reducing the fatality rate associated with the commercial fishing industry
- Raising awareness of and preventing the damage caused by passive smoking

I'm leaning towards commercial fishing but I haven't ruled out the others so far.