Related Rule
Germany
Practice Relating to Rule 29. Medical Transports
Germany’s Military Manual (1992) states that “any transport of wounded, sick and medical equipment shall be respected and protected”. 
Germany, Humanitarian Law in Armed Conflicts – Manual, DSK VV207320067, edited by The Federal Ministry of Defence of the Federal Republic of Germany, VR II 3, August 1992, English translation of ZDv 15/2, Humanitäres Völkerrecht in bewaffneten KonfliktenHandbuch, August 1992, § 617.
Germany’s IHL Manual (1996) provides that medical vehicles “shall under no circumstance be attacked. Their unhampered employment shall be ensured at all times.” 
Germany, ZDv 15/1, Humanitäres Völkerrecht in bewaffneten Konflikten – Grundsätze, DSK VV230120023, Bundesministerium der Verteidigung, June 1996, § 503.
Germany’s Soldiers’ Manual (2006) states: “Fixed establishments, vehicles and mobile units of the medical service, without exception, may not be fought.” 
Germany, Druckschrift Einsatz Nr. 03, Humanitäres Völkerrecht in bewaffneten Konflikten – Grundsätze, Erarbeitet nach ZDv 15/2, Humanitäres Völkerrecht in bewaffneten Konflikten – Handbuch, DSK SF009320187, Bundesministerium der Verteidigung, R II 3, August 2006, p. 5.
Germany’s Law Introducing the International Crimes Code (2002) provides:
Anyone who, in connection with an international or non-international armed conflict … carries out an attack against … medical units and transport designated with the distinctive emblems of the Geneva Conventions … in conformity with international humanitarian law, shall be liable to imprisonment for not less than three years. In less serious cases, particularly where the attack is not carried out with military means, the period of imprisonment shall be for not less than one year. 
Germany, Law Introducing the International Crimes Code, 2002, Article 1, § 11(1)(2).
Germany’s Military Manual (1992) states:
The parties to the conflict are prohibited from using their medical aircraft to attempt to acquire any military advantage over an adverse party. The presence of medical aircraft shall not be used in an attempt to render military objectives immune from attack. 
Germany, Humanitarian Law in Armed Conflicts – Manual, DSK VV207320067, edited by The Federal Ministry of Defence of the Federal Republic of Germany, VR II 3, August 1992, English translation of ZDv 15/2, Humanitäres Völkerrecht in bewaffneten KonfliktenHandbuch, August 1992, § 620.
In the Dover Castle case in 1921, a German court acquitted the commander of a German submarine of sinking a hospital ship and killing six members of its crew in violation of the customs and laws of war. The Court found that the commander had sunk the ship in execution of orders and could not, therefore, be held responsible for the ensuing violations of the law. 
Germany, Reichsgericht, Dover Castle case, Judgment, 4 June 1921, p. 429.
In 1944, the German hospital ship the Tübingen was bombed and sunk by the British air force. Following the sinking, the German Government issued the following official protest:
On 18 November 1944 at 0745 hours near Pola the German hospital ship Tübingen was attacked by two double-engine British bombers with machine guns and bombs so that it sank, although the course of the hospital ship had been communicated to the British government well in advance of its voyage to Saloniki and back for the purpose of transporting wounded German soldiers. Numerous members of the crew were thereby killed and wounded. The German government emphatically protests the serious violations of international law committed by the sinking of the hospital ship Tübingen. 
Germany, as cited by Alfred M. de Zayas, The Wehrmacht War Crimes Bureau, 1939–1945, University of Nebraska Press, Lincoln, 1989, pp. 261–266.