3D Printing in Shipbuilding

Introduction

Although the 3D printers first started in 1980s, they never caught on until very recently due to the cost of technologies involved. With the patents in fields of technologies such as Metal Laser Sintering expiring, and more and more open-source hardware being available, there has been an incredible hype about 3D printing in the shipbuilding and manufacturing industry. The caveat, however, is that it can be used currently to produce specialised parts with greater accuracy, however for mass production, it has not earned viability yet – due to its speed and limited material capabilities.

Diffuser ring made on an EOS printer using cobalt-chromium, printing after almost 10 hours

The journals and media are flourishing with products that we can produce with 3D printing capabilities and telling us to start looking forward towards the future in its scope. There are incredible efforts to print whole houses, boats, car frames with nothing but a 3D printer. 

Underwater drones being 3D printed for their structure

But, although a majority of the firms know the tremendous value of being able to print with nothing but raw materials, not many are able to identify where can they utilise these capabilities to be able to replace conventional parts. Although with time inspiration will strike, but for now, we remain as clueless as ever about an incredible technology and not knowing its far-reaching implications.

"I don't know what to do with it!!" Maersk introduced 3D printers on its tankers for manufacturing spare parts

In Singapore, we introduced an experimental advent into 3D printing capability – first of its kind in a shipyard - in the accommodation outfitting department. The printer was a MakerGear M2, able to churn out ABS models within no time and sharp accuracy. The goal? To be able to develop 3D modelling capability in STL formats, slicing and printing parts for everyday use when time is of essence (in short – the Toyota Just-In-Time approach).

Experimental Areas of Use

These are few areas we hadn’t guessed before which now came to us as apparent possibilities with something as basic as an ABS printer:

1. Replacing Teflon screws with ABS (only for plugging purposes and not when under load-bearing conditions, since Teflon is thrice as strong)

2. Customised door stoppers for accommodation doors

3. Customised brackets that might not be available among common suppliers, and used for lightweight furnitures

4. Other custom brackets with embedded items such as bolts or similar models (to be done with a pause-and-resume 3D printing method)

?Opportunities are aplenty, with 3D printers now being able to not only print in ABS/PLA, but sinter metals such as titanium and inconel, and thereby the onus is on the shipyards to identify possibilities of changing their businesses for better by using 3D printers.

Inflecting Reality on 3D Printing

In shipbuilding repair, where time is crucial, the turn-around times and dependence on suppliers for procurement can be greatly marginalised when it comes to parts that are often required to be shipped from other countries. For example, any of the above items might require a whole chain of procurement competence – between being able to identify suppliers, process purchase requests, place orders, deliver the goods, and receive the goods – incredible amount of time that was cut-short by availability of 3D model ready to go for printing and be done in flat 20 minutes.

So are we there yet? Being able to print large structures such as ships with next generation carbon-fiber and metal printers?

Case Study

Considering that we will not be limited by the size of the printer available – and we have an ultra-gigantic 3D printer, below is an example of a EOSINT M270 by EOS, a company very well known for its 3D printing products, having less than few cubic meters of print volume - a fraction of what a ship size can be - 177000 times smaller than the ship I'm working upon. 

EOSINT M270

Let us look at speed first: The maximum speed of the printer is 8mm3/s.

The lightweight for this patrol boat shown below is 500 tons. That is several times smaller than the big vessels that we’re accustomed to. But let's say we're going to print this one!

A 500 ton patrol boat hull structure

Considering steel has a density of 8050 kg/m3 and 1 ton is 907.2 kg, it gives us 56.34 m3 volume of steel required. Given the printer will print at its maximum speed, it will take us 7043478261 seconds to build the hull with nothing but a 3D printer. That means 223 years.

That means 223 years!!!!

Here is what life looked like 200 years ago

So you’ll most likely not get to watch the ship you started printing in your lifetime, or probably the next few generations combined. Currently, the timeframe of producing such steel structures is not more than 4-5 months, and thus we need to be 600 times better than what we are now to be able to cut short from 200+ years to 4 months. Which brings me to the second point – the cost.

Steel powder costs about US$7/kg. Hence requiring US$3.17 million for raw material alone. Now let’s check the electricity costs of printing using this gigantic printer! Since we printed for nothing short of 223 years. The EOS printer is rated at 400W, which makes us consume 0.8 GW of energy during the entire project (not accounting for moving parts energy consumption – such as overhead cranes, sliders etc). At a rate of 1 Kwh costing 12 cents, it will cost $100k for the electricity costs, not a staggering amount as I’d thought it might turn out to be.

So, we’re not really limited by the pricing, but more by the speeds of printing offered. The only case this is offset by other factors is when lead times are higher, whereby it makes sense to produce on the go.

Coming towards the end of discussion, we might not be able to produce cheaper parts than mass manufacturing with 3D printing, and maybe we might equal mass-manufactured products based on cost of products. Perhaps 3D printers would also begin being installed in several mass-manufacturing facilities to be run parallel. But, in all, one consideration that has to be paid attention to in introducing 3D printing are its not-so-desirable speeds. 

So how far are we from there?

With upcoming horizon technologies such as CLIP (continuous liquid interface printing), which is several times – 50 to 100 times faster than conventional methods, it might be possible. So will we hit the 600 times speed mark? Possibly in the next 9-10 years.

So will we hit the 600 times speed mark? Possibly in the next 9-10 years. 

Carbon3D - a company based on CLIP technology

Time comparison between CLIP and SLS/SLA - of course this could be quite an optimistic comparison

Seeing the optimistic outlook towards the future, let us look forward to it with fingers crossed and be a part of this great innovation, to produce things like we never predicted before. Perhaps the CFRP structures could be printed with 3D printers utilising adhesive of different grades and enforcing layers over each other - just like MarkForge 3D printers.

You might just as well start having a 3D printer by your bedside next time for essential items and fiddling with your self-designed models!