Qutab Minar has a natural tilt

Qutab Minar, the 72.5 metre high Tughlaq-era structure, is one of the three world heritage sites in Delhi, the other two being Humayun’s Tomb and Red Fort. According to some historians, Qutab Minar has a ‘natural’ tilt which occurred not when it was built by Qutubuddin Aibak in 1173, but was caused either when the two upper storeys of the monument were later being built or due to an earthquake. Inevitable comparisons with Italy’s Leaning Tower of Pisa are being made as well. Although intended to stand vertically, the minar began leaning to the southeast shortly after its construction. Experts say its foundation is poorly laid and loose soil around it allowed the structure to tilt. Apart from the tilt, the damage to the 13th century monument from rainwater is clearly visible on the surface of the minar. On the southwest side, part of the semi-circular and angular fittings on the outer facade have blackened and huge cracks have developed due to underground water moving up the walls due to capillary action. ‘‘The discolouration is clearly visible. We have to ensure that there is no water seepage in the monument’s foundation. Till now, the tilt is within safe limits but it could increase. We will also treat the damaged portions of the Minar,’’ said a senior official. According to sources, the tilt was mentioned in ASI reports as early as 1950. In the 1960s, a UNESCO-funded research conducted by a Japanese team submitted a three-volume report on the tilt. A report by archaeologist Zafar Hasan also pointed to the tilt in Qutab Minar, saying it needed to be controlled at the earliest. Officials from ASI, however, insist there is no cause for alarm. ‘‘We have taken prompt action to tighten the water channels around the minar foundation. We can’t undo the damage already caused by the capillary action but a weak foundation is common in other monuments like Taj Mahal, Agra Fort and Red Fort. It is more of a concern for Qutab Minar because of its great height,’’ said a senior ASI official. Like the Leaning Tower of Pisa, Qutab Minar's foundation needs strengthening. However, it tilts much less than the Italian wonder — which tilts at an angle of 3.97 degrees With Delhi situated in a seismic zone, Qutab Minar experiences occasional tremors. Experts fear that this, combined with unstable soil conditions, could aggravate the tilt In the 1970s, ASI checked the minar's verticality and detected a 25- inch tilt to the southwest. It was observed that for a 47 feet diameter base and 238 feet height, the tilt was not serious