Boat Pit Graffiti
Quarry marks inscribed on the lower surface of block No. 20. from the first of Khufu's boat pits to be opened in 1954. Djedefre's cartouche can be seen amongst the graffiti.
"There were also found some reddish quarry marks on the surface of the huge blocks after the removal of the compressed layer previously mentioned. Other reddish or blackish marks were also found mostly on the northern, southern and lower surfaces of the blocks.
Eighteen cartouches bearing the name of King Dedefre, the builder of the incomplete Pyramid at Abu-Roash were found among the quarry marks on the upper surfaces of blocks Nos. 15, 19, 20, 23, 30, 34, 35 and 40, the lower surfaces of blocks Nos. 5, 7, 9 and 20, the northern sides of blocks Nos. 34 and 38, and the eastern sides of blocks Nos. 5 and 33 (PI. XI, A).
It is obvious therefore, that this king had succeeded King Cheops. Consequently, the assumption of some historians that King Dedefre ruled at the end of the Fourth Dynasty is untrue.
Though Dedefre did not build the discovered boat for his father, he at least completed it. History is full of such examples.
On the lower surfaces of blocks Nos. 2,4,5,6,7,8,9,10,11,12,13,15,16,17,20 and 40, the marks include some measures, namely, the length, width and the height, the unit of which was the Ancient Egyptian cubit which was 52.3 cms. (PL XI, B). An account of all the marks will be given after their decipherment and study. "
From The Cheops Boat, Part 1, by Mohammed Zaki Nour, Zaky Iskander, Mohammad Salah Osman, Ahmad Youssof Moustafa.