Ballast in F1

Have you ever heard the phrase: "Details are important, because they build the whole"? Probably not, as I just made it up. When we talk about Formula 1, there are as many as 15,000 little details (some cite 80,000, probably including the bolts) that build an F1 car. This is why the details are important just as in every engineering creation. This time we will talk about ballast and its role in Formula 1.

F1 Car weight 

Generally, a bare-stripped F1 car weights about 535 kilograms - no driver, no fuel, no fluids whatsoever.
In the past, different rules have reigned the weight distribution, but today the 2013 rule book says: 642 kg minimum, including the driver, but not the fuel.
In regards to weight distribution:

For 2012 and 2013 only, the weight applied on the front and rear wheels must not be less than 292kg and 343kg respectively at all times during the qualifying practice session.

Let's use Pirelli's test car model to better illustrate the load and the changes:

Image source: racecar-engineering.com

So, in order to satisfy those requirements and sometimes to supplement a specific design considerations, teams use ballast. How exactly does it look like? Example:

Copyright: Caterham F1 Team

Both pieces look about the same, right?
The thing is that one of them is made of aluminum, while the other is made of Tungtsen steel, also called Densamet. OK, what's the difference, the reader asks? Well, the weight of the aluminum one is about 800 grams, whereas the Densamet plate is about 9 kilograms! You can certainly feel the difference when you try to pick up and hold each one of them:

Aluminum, just four fingers

Tungsten - you need a whole palm

One of the most interesting characteristics of the latter is it UTS, or Ultimate Tensile Strength - about 900 MPa. If that number doesn't speak much, the human skin's number, for reference, is 20. Certainly, the density of such piece is also very high, with value of around 18100 kg / m^3. For a typical iron it is around 7,870 kg / m^3.
I hope those numbers will be able to help you grasp why those little pieces could be very important in terms of setup.

The shape of a ballast could be really different and can be modeled based on team's needs. Another example is here:

Originally found here http://berkemceylan.wordpress.com/2011/10/30/i-f-o-identified-flying-object-ballast/

The rules say that: "Ballast can be used provided it is secured in such a way that tools are required for its removal. It must be possible to fix seals if deemed necessary by the FIA technical delegate."

Where - position

After we have clarified the physical dimensions, the next question we are going to answer is where to put ballast. Typically, ballast is put in front of the car - posistions such as under the nose cone, front wings and T-tray. 

Another example, in racing conditions is under the gearbox - very low, obviously, to keep the car's Center of Gravity low.

Twitter.com, Red Bull

Placing 10 kilograms in a car that weights about 500 kilograms can have profound effect on the handling characteristics during the course of an entire race. Also, having the option to fit such small pieces with relatively high weight is really helpful when we talk about proper setup for drivers like Robert Kubica or Mark Webber - both around 184 cm.