Silent Stairwell

The Silent Stairwell is the collective designation for any vertical circulation shaft within the Tower in which sound is not carried between landings. The condition is architectural rather than miraculous: the Office of Acoustic Survey has confirmed it in shafts of brick, speckled limestone, poured aggregate, and, in one contested instance, compressed paper. What distinguishes a Silent Stairwell from an ordinarily quiet one is that the silence persists under load — a party of forty may ascend a Silent Stairwell in conversation and arrive at the upper landing with no recollection of having spoken, and with their voices intact.

Silent Stairwells are not a floor, a sector, or an annex. They occur, and the Tower has never satisfactorily explained why. The Office of Stairwell Verification maintains the register; the register is incomplete; the Office maintains that this is because the condition is intermittent, and the Bureau of Vertical Records maintains that it is because the Office is slow.

Identification and the flag protocol

Because silence does not announce itself at the threshold, surveyors require a positive test. The standard instrument is a struck bell of 180 mm diameter, carried in a felt sleeve, rung at each landing during descent. If the tone is heard on the landing above but not on the landing below, the shaft is provisionally silent and the surveyor marks the newel with a cloth flag in the Office's grey.

The flags are removed by the next descending surveyor and returned to stores. Surveyors are reminded that the flags are not to be taken home. The reminder appears in the standing orders of the Office of Acoustic Survey, Clause 9, and is repeated because it has been necessary.

Registry and the disputed count

As of the last general survey, the Office of Stairwell Verification recognises fourteen Silent Stairwells in the upper archive and an unreconciled number below the water line. Several are already familiar under separate designations. Pd H 71243, the designated silent stairwell linking Floor 112, Annex B with the Cartography sector of Floor 43, is formally a Silent Stairwell that was registered under the object catalogue before the category existed, a clerical accident that the Office has declined to correct on the grounds that correcting it would require Annex G to renumber its holdings. The Backwards Stairwell in the Ninth Stairwell Annex was assessed as silent in Cycle 5,401 and confirmed silent in Cycle 5,402 by a surveyor who descended it the wrong way and heard nothing at all, which the Office accepted as evidence on the narrow ground that it was the correct result arrived at incorrectly.

The Silent Choirs were placed in jurisdiction over one such shaft under the 91st Concordance for observational auditing of Stairwell Beta, an appointment that has never been rescinded and that the Choirs have interpreted expansively.

Governance: 44-E and the silence clause

Silent Stairwells are governed under the Stairwell Calibration Ordinance 44-E, whose Schedule 3 sets the permitted tolerance for sound attenuation at four landings' separation. Schedule 3 was drafted for calibration shafts and was extended to silent shafts by the Stairwell Calibration Ordinance proper, an extension that its own preamble describes as "provisional pending survey." The survey has not concluded. Stairwell Calibration of a Silent Stairwell therefore proceeds under provisional authority, and any challenge to a calibration rests on provisional authority, which is why so few challenges are brought.

Disputes over the count have run for some eighty cycles. The Bureau of Vertical Records holds that a shaft is silent if no sound crosses a landing, and counts accordingly. The Office of Stairwell Verification holds instead that a shaft is silent if the Office has declared it so, and points to Clarification 44-Z, which classified Stairwell Zeta as a hybrid-variance shaft rather than silent despite a measured attenuation indistinguishable from silence. The Bureau has called Clarification 44-Z "a filing decision dressed as an acoustic one" (Bureau memorandum, Cycle 5,388, unpublished), and the Office has not replied.

The Orchard case

The most cited incident in the literature is the Orchard descent of Cycle 5,412, when a surveyor named Halloway Orchard entered a shaft on Floor 3,306 with a party of six and a bell, and the bell was not heard again. Orchard's party emerged at Floor 3,301 in good order. The bell was recovered eleven cycles later, resting on a landing, undamaged and unwarmed. The Office ruled that the shaft in question was not silent but "delayed," a category created for the occasion and never used again, and that the bell's recovery demonstrated the shaft's compliance with Schedule 3 rather than its breach. Orchard protested that a shaft which returns a bell eleven cycles late cannot be said to conform to any schedule. His protest is preserved in the register with the word noted beside it.

"The shaft conveys; it merely conveys at its own convenience. The Ordinance does not specify a deadline."

— Office of Stairwell Verification, ruling of Cycle 5,413

Sound policy and visiting

The Silent Choirs hold that a Silent Stairwell should not be entered with the intention of hearing anything, on the ground that intention itself may be carried. The Office of Acoustic Survey holds the opposite, that a shaft entered without a bell is entered unverified and returns unverified. Both positions are cited in the register. In practice most descents now carry a bell and no expectation.

Visitors are asked not to whistle in a Silent Stairwell. The prohibition dates from an incident on Floor 8433 involving a shaft adjacent to the Whispering Stairwell on Floor 8433, which for six days whistled back. The shaft in question was subsequently found to share regulatory lineage with Stairwell 12-γ and to be silent only above the seventeenth landing, and the protocol for partial silence remains, like the register, incomplete.