In order to make the mold, first you have to make the mold plug. The plug must be exactly as you want the finished hull to be.. nothing less than that. Back when I was researching for this project, I quickly found that it was impossible to obtain any details regarding Emma, and blueprints for Emma was completely out of the question. The only available data was the length and width and such of the entire hull. No measurements on superstructure, cargo hatches or anything. (I even asked Maersk directly, but they too could not help me, politely referring to the competitive nature of that sort of data. For that same reason I will not list my findings here.. that would be kind of wrong I think.)
How to proceed? I got hold of as many images as possible, and started with one known measurement: The world wide standard 40' containers.
I found an image where the containers were visible close to other key features. From measuring the containers in the image, and from knowing the real measurements of containers, I could calculate a scale for that particular image, and measure + calculate the measurements of other things near by. This process was repeated again, again and again, and step by step, feature by feature, picture after picture. I worked over the entire upper hull, deck and superstructure.

A few tips:
1) Get as many images as possible, and print them.
2) Find at least two measurements for every detail, and compare your findings. Use an average if in doubt.
3) Remember two words: "Perspective" and "Distortion".
Imagine an image shot from the water surface close by the ship, up along the side of the ship, towards...say the bridge. The calculated scale for the letters on the side of the ship would then NOT be the same scale as you would need to use for details further away from the camera. Far from... Use images shot at a distance, straight on, or from the side at a 90 degree angle if possible to support the close-up's.
4) Use things like the railing to double check your findings. The height of railing is pretty much the same all over a ship. ;-)
5) Make a lot of coffee!

Normally a model builder would make a skeleton with a keel beam, and many frames / ribs along the entire length, but since I could not obtain any hull information / blueprints, then this method was not an option. Instead I had to rely on my measurements, and the many, many images.
After estimating the expected weight (thus displacement) of the finished model, then the under-water part of the hull could be decided as well.
Finally: It was time to build the mold plug.

With the images in one hand, and the a lot of time in the other, I started to shape the plug. Filing, comparing images and plug, filing some more, comparing, applying house filler, comparing.. Changing angles to match other images, moving light to match the light angle in the picture (important!), comparing and adjusting again. And again, and guess what... again. After a while the plug started to look very much like the ship in the images. Having shots from many different angles allowed me to "see" the hull shape in a 3D-like way in my mind, which again helped shaping the plug far better than I has hoped for. (Another tip: Do this work only when you are not tired. The "3D-mind-thing" is exhausting, and does play tricks on you if you are tired.) New images came available during the work, and they all stared to match straight off when I took them to my plug, and compared. That confirmed that I was on track!

To aid the general hull shape seen from above, I have put together a mosaic from Google Maps to the right. The image is from when she was build at Lindoe, and shows the floating but not yet finished hull. Note that you can zoom in for a lot of details, and even look inside the hull, and cargo bays. Visible on the peer is even some cargo hatches in various sizes. Click here to download the 12.7 Mb image in PNG format. (Fireworks etc.) Click the image to the right to view it in your browser, and then right-click it to save it as a JPG. The hull pictures below are divided up in three key areas; the entire ship, the bow and the stern.

More images can be found in the Picture gallery.

Hull:

Bow:

Stern:

Making these stencils allows me to keep tight control with the rest of the hull work. The two wooden stencils will aid the cutting of the foam block, and further shaping of the hull. And yes, there is a typing error on the one for the stern (which is also the hull shape of the stern below the waterline), the beam is 25.45 cm, not 25.54 as written. In the background: My 1:82 scale SSBN submarine awaiting final trim and last parts.

This is the block of expanded polystyrene that will be the core of the hull plug for the mold. I got it out of a dumpster at a construction site for the price of one Cola... Next is cutting it to be a bit smaller than the finished hull, covering it with plaster or clay, and do the final shaping.

The stern was fairly easy to do. The stencils really helped shaping the raw mold core. The angle of the underside of the stern, going from the lower edge of the stern wall, and to the bottom of the vessel was copied from real life images. The black lines here and there are the remains of support lines, used for shaping.

The bow is a different matter. A stencil of the bow contour was made from the satellite image. Then the bow angle was copied from a real life image, and with these two, raw basic lines, the rest of the shaping could begin. Many images was lined up, and shaping began. Slowly filing and sanding away, while comparing to real life images. Then the blue cardboard stencils was made. One of the ten is shown on this image. The mold plug extents beyond the planned deck edge. The idea is that this will produce a nicer deck edge if the fiber glass is cut, rather than molding right to the edge.

The center line was drawn on the inverted hull, and with that I could move the stencil to the other side, making a perfect mirrored copy of the bow area, like shown. Ten stencils gave me one for every other inch, sufficient to get it right. (The side of the bow shown in the picture is not finished.) Tip: Use yellow ski glasses when working white materials. That makes the reflective surface far easier to see, and work.

This is the filler that I have shaped the hull in over the foam block. It's easy to apply, dries over a couple of hours, sand to a very smooth surface, and is great to work with. This ready-to-use mix was even cheap, and saved me from the mixing powder and water mess. This is a 10 liter (2½ gallon) portion, WAY enough for the hull work. I applied it with a couple putty knifes, sticks and hands... then ran the stencil in the tracks.

After the foam was formed, a layer of the ordinary household filler (above) was applied in a layer app. 1/4" thick. It was sanded after hardening. These two plates formed the base for smoothing the stern, and ensured a 100% flat wall.

In the same manner as mentioned above, the stern part of the bottom was made. The alu rails gave the 11 degree angle, and the stencil the shape. A couple of layers was put on, and finished off with some light sanding. The idea is to cover the hole hull with epoxy resin later on, and sand that to 100% perfection. This surface will be the finished surface, that the mold will build on. Let's see how it turns out..

Same procedure as above. Apply filler, run shape-tool in the tracks. Repeat until close to perfect. Allow to dry, run again, allow to dry. Then sand. Pretty straight forward, and fun! The bow will be another story, but I have invented a small tool for that too. The trick is to apply an even layer on the already correctly shaped bow, and then repeat it on the other side...

This is the very beginning of the stern tube. The very middle of the hull was found, and a channel was cut. Then a wooden stick was molded into this channel in the right position. Because my hull will not the proportional when it comes to the depth, then the stern tube will not be 100% like the real thing... but close!

This images shows the wooden core being covered up, using the same house filler as above. When this dries I will go forward and add the remaining filler, giving the final shape of the stern tube. It is very important to observe the prop's diameter when fitting this!

Here's the finished stern tube. I have been forced to come to a small compormize with the hight, because I must use an over-sized screw on the model. This has caused the stern tube to be closer to the hull than if it was true to scale, but it still looks right.

This is the special tool I mentioned earlier. The problem is that I need to add app. 6mm (1/4") to the otherwise, shapewise finished plug. How to do that evenly? This tool does the trick. Half an hour in the shop, and it was there.

This illustrates how it's used. There is no moving parts, so service is reduced to simple cleaning. This hole problem would not have been there if I had shaped the bow in the final material, rather than the expanded polystyrene, and adjusted with filler.... but hey, I'll get there.

Here's the bow area that has been worked with the special tool. First a thick layer of filler was applied, and the the tool was used to smoothen it, while ensuring a layer thickness of app. 6mm (1/4") When it dries, I'll sand it slightly, then fill out the tool tracks with filler, and then smoothen the hole thing in one sweep.

Here is the sanded, and now complete starboard side. Next is to make a bunch of stencils, so the shape can be replicated / mirrored to the other side. Why stencils again? A flaw was discovered in the bow shape, so I have to once again replicate and mirror the shape to the other side.. lesson learned.

Here is the soon completed port side of the bow, and the final touches to the mold plug prior to the epoxy coat. Copying the other side to this side was fairly easy using card board stencils, but it must be observed that the are held in the right 90* angle at all times! The red drawing on the hull is where filler must be added to correct flaws, before more sanding. If looking carefully on the very top, you can see the 1" steps that represent the measuring point for a template / stencil.

When the shape of the plug was 100% done, I then painted the plug with pure resin ("pure" = resin + hardener, but no fiber cloth) a few times, and sanded it to the smoothest surface possible. Making the mold right on the house filler surface is not recommended. It is smooth, but not smooth enough. After sanding the resin surface then it was treated with wax, more wax and then some wax. Then a few coats of mold release agent for epoxy was applied, so that I was SURE that the later applied epoxy for the mold halves would not stick to the plug. (Image is prior to sanding, but after three coats of resin.)

(Content as work progresses)