Technical Drawing Fill

Question

So far I have my drawing like this:

Having this code:

\documentclass[14pt,letterpaper]{report}
\input{Preamble}


\begin{document}


\begin{tikzpicture}

\draw[double,double distance=5mm]
  (0,0) -- (1.5,0)--
  ++(0,-6cm)
  arc[start angle=180,end angle=360,radius=4cm] --
  ++(0,6cm)-- (11,0);

\draw[--](0,-.264)--(0,.264);
\draw[--](11,-.264)--(11,.264);
\end{tikzpicture}

\end{document}

I wanted to fill the middle space just like any other technical drawing like this:

Is that possible? How can I do that? the books and manuals are just too enormous to read. I'm sorry for being lazy.

Answer 1

The following specifies the outline, which is filled with a red pattern and drawn with a black line:

\documentclass[14pt,letterpaper]{report}

\usepackage{tikz}
\usetikzlibrary{patterns}

\begin{document}
  \begin{tikzpicture}
    \filldraw[
      pattern=north east lines,
      pattern color=red,
    ]
      (0, -.25) -- (0,.25) -- ++(1.75, 0) -- ++(0, -6.25)
      arc[start angle=180, end angle=360, radius=3.75]
      -- ++(0, 6.25) -- ++(1.75, 0) -- ++(0, -.5)
      -- ++(-1.25, 0) -- ++(0, -5.75)
      arc[start angle=0, end angle=-180, radius=4.25]
      -- ++(0, 5.75) -- cycle
    ;
  \end{tikzpicture}
\end{document}