Testing of small sized floating honeycomb modular structures in Cartagena Colombia - modular cube floating structures, catamaran floating elements, plate float elements... floating concrete building methods overview
It is clear that industrial floating structures can be built from concrete and have already aquired a amazing performance record that can not be matched by any other building technique - the question is how can we apply that on smaller floating structures of moderate size. Running a small building site in Cartagena .
honeycomb floating concrete structures of industrial size has been built in the early 70 ties - so the question was how small can you build floating honeycomb structures - the answer - see photos above - 1m cell size is feasible.
it is seems much more economic and feasible in logistics and materials to build a floating honeycomb along the lines of condeep baseplate structures , similar to glomar CSDI or similar to Nkossa. Than doing some "messy process" like foam on large scale.
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That kind of honeycomb has not only been built and tested for 3 decades on open ocean already - it is also clear that you can downsize the building size to just a few squarmeter of floating structure as we have done it here in a couple of experimental projects in cartagena.
A "cell size" of about 1m diameter works just fine.
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What form, shape, building method the cells of a modular island have is more or less trivial and without any major importance. Balls can work just the same as cubes or hexagons - just don't overengineer it - keep it simple keep it doable in mass production, keep it doable by an average concrete worker. (see more)
What really matters is that you can build a ton of buoyancy with 2 workers in a day at a cost of 166 USD (that are the global figures we have achieved already on our pilot projects sites) - and you can go on building and growing your modular islands as long as you have money in the project account to support building.
Question regarding "a ton of bouyancy". Does that mean that the total mass of the cells is one ton, or that the cells produced in one day will support one ton of mass above the waterline?
Good post with practical, functional information and application possiblities.
-- Edited by Brannok812 on Tuesday 29th of November 2011 09:34:58 AM
You obviously have a great deal of experience with concreate for this type of application. You have proven repeatedly that concrete is very cost effective. I was wondering if you have perfomed a simiar experiment with alternative materials, such as terra cotta. I am thinking of a floating structure or submersion of less than 10m. The cost differential may not be there vs the loss in performance characteristics. I am interested to see if the cost for a stationary platform could be driven even lower than the very reasonable mark you have established.
-- Edited by Brannok812 on Wednesday 30th of November 2011 05:58:34 AM
The ton of buoyancy per day is a very global production figure, outcome of real world pilot projects and test runs - it means that you get a construction volume output of 1 cubic meter per day that is capeable to support 1 ton of weight above the water, in a building site that has a all inclusive function cost of USD 166/day.
And this is the smallest project size possible. USD 5000/month cranking out 30 cubic meters of structure per month.
All kind of shell building submarines, surface floats, honeycomb floats, catamaran floats, plate floats, are inside this global frame - form and size of the build change little on this global frame.
Terra cotta is certainly a material that lasts in marine ambient - but i doubt that you can have a efficient building process that can rival with concrete shells. In certain way you can take bricks as terra cotta ...
Sure that costs can be driven lower than the mark we have established already - in project management there is never a point where there is no room left for improvement. The mentioned frame is just a reference where we stand today.
Wil, can you provide the following information so I can develop a business plan for Rincon? I've consolidated from a couple of other posts.:
At a basic level, what valuation shall we place on the platforms deliverable to the buyers. If we use $166/ton of discplacement as the building cost, what will be the final sale price to the buyer, and how long should we allow for the sale to complete? Also, is that a metric ton or imperial ton, 1000 kg or 2000 pounds. Also, what is the density of the concrete, interior and exterior wall thicknesses, floor thickness, deck thickness, and span between interior wall or bulkheads.
At this point we need to settle on a multi purpose float design and cost it out. Wil, can you give me a figures for $/cubic meter of finished ferrocement, exterior wall thickness, interior (cell) wall thickness, floor thickness, ceiling (deck) thickness, cell size. It would be best to put together a parametric spread sheet, i.e. float depth, cell size as variables, exterior wall thickness, interior wall thickness, floor thickness, ceiling thickness as calculated values. With this, I can lay out designs in a parametric CAD modeler. Also, we should separate out the fixed costs, i.e. administrative salaries, equipment, rentals, from the variable costs, i.e. concrete, steel, water, labor, other materials, and delivery costs to customer or local anchorage. We also need to determine the sale prices to the local markets you described for the floats. A fixed price per ton of displacement or floatation isn't really detailed enough seeing as for a roughly cubic or cylinderical configuration, cost should increase by the square while enclosed volume increases by the cube, so cost per cubic meter of volume or ton of displacement should decrease with an increase in size, though there will be some increase in wall thickness ofr larger enclosed volumes.
admiral, let me first say that Numbers should never been written based on imagination but should emerge from the real construction situation of a real world pilot project. You must also have clear that numbers depend a lot of the phase a project is in.
In the starting phase you burn the budget exclusivly for finding a place, make it adequate, get tools, protect it against third party interference, etc... in this phase the production is cero and crunching the numbers is of no value as the numbers don't give you a decision base of anything the processes to run in this early phase are arbitrary random depending on the unique specifics of the building site you just have to do what needs to be done to get production up and anything costs money.
Crunching numbers starts to make sense when the project enters into a stable production phase. I would not talk about a "stable production phase" until you have some 20m of floating structure in the water so you can speak about a "seasteading project in the saddle".
Now let's talk about the kind of "minimum engine" you need behind a "seasteading project in the saddle" - you can not make a worksite smaller than 1 worker working. In practice you need 2 workers that can assist each other, and a watchman keeping the site safe and the tools from disappearing at night. So you start with paying about 3 salaries. Anything less is a mess.
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Such minimum building sites can look the way as shown in the pictures above - a shadow roof, 2 workers, a basic production - can be a 200 ton sub or can be a series production of cubes for a modular platform.
In any case the set up and running of the building site will cost about the same. 2-3 worker building sites have a kind of fixed cost of operation that is basicly driven by the labor material and asociated costs which can be VERY different from country to country.
So when i talk about cost per cubic meter i talk about setting up that kind of building site, operate it and cranking out product under the conditions of Colombia in a building site where people are treated well and no social dumping is happening.
Running such a site costs about 166 USD/day - and once established a "workflow" you can expect to crank out 1 ton of structure dayly.
It does matter very little what you build can be cubes rafted up, can be a catamaran float element, can be a plate seastead,
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Running a basic building site in Colombia always will cook down to something like 166 USD/day in pure base cost of function.
In ideal conditions (stable work flow, no third party interference) this site once established can crank out a ton per day.
But this figure includes the presence of a site manager who knows to motivate the people properly and keep the workflow up.
As we all know if you cut out this factor people will just sit in the shadow and crank out nothing...also this production will not happen in the start up phase, not on days of tropical rainfall, not on days when authority and yard management interfers...etc.etc...
So a realistic figure that includes all those factors for a build of a real world construction of 200 tons will be 93.000 USD -
We actually promised a construcction in that budget and we did it in that budget. That would be 480USD per ton of construcction.
Brought to life in a real world project in Colombia.
Those are the numbers to crunch and they are realistic numbers.
You could assign those numbers to a project phase A (starting phase) where you establish a project at a rough cost of USD 480 per ton while you hammer it out until you have a 20m object in the water and with it a seasteading project in the saddle.
And then a project phase B where you have overcome most obstacles and work in a constant workflow on a 20m modular growing building site costs dropping down to some 166 USD/Ton.
For doing a spreadsheet you need to take those cornerstones and fill in all the detailed number crunching that a investor will want to see between them in reasonable proportions.
Keep the material costs realistic (a 50 kilo sack of cement in Cartagena is 22.000 pesos) a rebar 6m is 20.000.
Worker minimum wages 514.000 Pesos.
You can size up building sites just multiplicating the basic worksite figure.
You can estimate a building time from the volume of the build and the number of workers working on it.
All scales linear - as you need the same effort for each ton - no matter how big or small the build is.
Figures only will change if you start to put in mayor effort savers like concrete pumps, premix factory ships, etc. - which you will certainly not in a start up phase.
The wall thickness for honeycomb structures is 5 cm (all walls) - cell size is 1m.
We have experimented also with increasing cell size to 2m - seems to work well
Monolithic structures like domes, blimps, spheres, and other shells, should be calculated as one cell where the wall thickness is 1/20 of the structure size.
Yes, what I'm getting at is to determine an ideal balance of manager and workers since this is a labor intensive project in the startup phase. It may be better to have one manager with 4 to 10 workers to build much faster and reduce overhead as a percentage of production cost.
Now we just need a final sale price per ton of displacement to project profit and loss. I'm assuming we will build at Rincon and sell locally per your suggestions.
It would also be nice if we could get the honeycomb cell size up to 3 meter cubes so they can be used as rooms.
Finally, what is the density of your concrete/ferro mixture?
Management - it works well on a colombian building site to have 1 manager overseeing and handling a maximum of 12 workers.
What concerns sales price a squaremeter of working barge in honeycomb structure here in Cartagena is sold at 1920 USD so there is a Factor 4 between our production cost (in the less favorable A phase) and the general actual barge sales value in the zone.
We could argue that our barges have 200 years of maintenance free service life and a steel barge only lives for 2 years maintenance free in tropical salt water conditions. So the "value in service days" of a concrete barge would be a hundred times higher. But we do not know if the buyer market would follow such agruments and actually buy and pay them until we do actual sales.
So i think it is a prudent approach to target a sales price equal to a steel barge which leaves us with a factor 4 between production cost and retail sales price. That seems to be a comfortable space considering that production cost,once we reach B phase still can go down due to a efficiency increases in the production.
Base for the squaremeter barge calculation is a honeycomb with 1m cells and 5cm walls a squaremeter deck space would require about a ton of material to build and can be done in one day. Tweaking the cell size as you suggested we still have considerable potential for cost reduction - but it seems prudent not to take the concept to the limits in the basic business plan calculations. Tweaking the cell size has structural and constructive limits due to proper compartimentalization of the build and rughness of the build in dayly use.
Basicly the bigger the float becomes the bigger the cells can be.
The building material density is 2,4 and the steel component is 1/16 in weight.
Means 16 tons of concrete need 1 ton of steel reinforcement, 4-5 tons of cement.
Strong and light structures in compound curves. Land based and water based honeycomb structures (last picture the structure of the WHY yacht). It is obvious that honeycomb structure building will cook down to a similar price per squaremeter living space cost - no matter if it is performed on land in a building or at sea in a floating structure.
Concrete has clearly emerged as the most economical and durable material for the building of the vast majority of marine structures. Reinforced concrete too has overcome the technological problems making it
a suitable material for the construction of advanced marine structures such as offshore drilling platforms, superspan bridges and undersea tunnels. As the world becomes increasingly ocean-oriented for energy
and other resources it is predicted that construction activities during the 21st century will be dominated by concrete sea structures. The performance of concrete in the marine environment is presented here
in a logical manner giving state-of-the-art reviews of the nature of the marine environment, the composition and properties of concrete, history of concrete performance in seawater, major causes of
deterioration of concrete in the marine environment, selection of materials and mix proportioning for durable concrete, recommended concrete practice and repair of deteriorated marine structures. It is of
value to any design or construction engineer responsible for marine structures.
-- Edited by admin on Thursday 15th of March 2012 11:08:19 PM
The “Guidelines for Adaptation to Climate Change in Cartagena de Indias” (Lineamientos de adaptación al cambio climático para Cartagena de Indias) document was recently published in Cartagena, Colombia under the auspices of the CDKN-funded project “Integrating adaptation to climate change into local planning and sectoral management in Cartagena”. This Spanish-language publication provides decision makers and civil society actors with a timely practical guide for adaptation planning in the coastal Caribbean city of Cartagena de Indias—a complex urban setting in which thousands of poor inhabitants have already been displaced by recent extreme weather events. The application of this planning tool promises to not only set Cartagena on a path toward concretely addressing its vulnerabilities to climate change, but it offers an opportunity for the city to strengthen its competitiveness and become a model for other coastal cities around the world which face similar risks and impacts.
Authored principally by Colombia’s Institute of Marine and Coastal Research (INVEMAR), this publication represents a pioneering effort by local institutions, private and public sector actors, and civil society to identify and raise the profile of the challenges and opportunities that climate change vulnerability and adaptation present for Cartagena. Based on scientific research, technical criteria, and the inputs of a wide range of stakeholders, this document provides a synthesis of critical issues and the basic framework for the development of Cartagena’s plan for climate change adaptation. It summarizes the most strategic climate and development issues facing Cartagena in the short, medium, and long term. These notably include the loss of economically significant beaches to coastal erosion, deterioration of environmental services and resilience, declining fisheries, proliferation of tropical diseases, and the impacts of flooding on housing, industry, infrastructure, and the city’s iconic colonial center.
The publication was launched in Cartagena on June 28th at an event which was well attended by a wide range of local and national stakeholders, including the Ministry of the Environment and Sustainable Development, Chamber of Commerce of Cartagena, Secretariat of Planning of the Mayor’s Office of Cartagena, District Secretariat of Planning, Port of Cartagena, and local non-governmental organizations. With continuing support from CDKN, the next step for Cartagena is the development of the city’s climate change adaptation plan which will include specific adaptation measures and projects.
Testing of small sized floating honeycomb modular structures in Cartagena Colombia - modular cube floating structures, catamaran floating elements, plate float elements... It is clear that industrial floating structures can be built from concrete and have already aquired a amazing performa...
cartagena colombia, floating concrete, honeycomb and shell structures, concept testing, it is clear that giant industrial floating structurs can be built in concrete - oil/gas industry has widley tested and implemented that concept already. The interesting question is, how small can you actu...
It is clear that industrial floating structures can be built from concrete and have already acquired a amazing performance, but what about the same on concrete driveways on floating homes!! Any ideas?
I do believe all of the ideas you’ve offered to your post. They’re really convincing and will certainly work. Still, the posts are very brief for starters. May just you please lengthen them a little from next time? Thank you for the post. Fullz Dob SSn DL