The Relevance of a Survey Plan
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Some people like to ask ‘what is the relevance of a survey plan?’.
A survey plan’s primary purpose is to prove the identity of a land which comes handy when a dispute ensues.
A survey plan becomes of utmost importance for any success to be attained in any land suit. A plaintiff seeking for declaration of title to land has a cardinal duty to show with certainty, the area of land being claimed, failure to do so makes his or her claim to be at risk of being dismissed.
Hence, a land survey plan is a specialized map of a parcel of land, created by thoroughly examining and measuring the property. It determines and delineates boundary locations, building locations, physical features and other items of spatial importance.
More than just a diagram of the property, a land survey plan is an important legal document that displays the exact legal borders of the property and applicable aspects of the registered title.
The definition of a surveyor according to Section 2 of the Survey Act means a “Surveyor licensed or deemed to be licensed under the Surveyors Registration Council of Nigeria Act”
The purpose of a survey plan in a land dispute is to show graphically the morphology of an area in dispute, its extent and size. Where a plaintiff desires to draw up or cause to be drawn up a survey plan showing the land in dispute, such a plan must show clearly the dimensions of the land, the boundaries and other salient features. That is how delicate a survey plan is.
There are instances when a land survey plan becomes inconsequential in a land litigation or in the proper determination of issues arising from a land suit. The court considers in such instances the necessity of survey plan for the proper trial of the action. Therefore a survey plan is not necessary at the under-listed times;
1. When there is a proper identification of the disputed land via the evidences put forward or admitted into court.
2. Where the land in dispute is known to both parties or is clearly ascertainable whether from the averments in pleading or otherwise and its area, exact location and precise boundaries on the ground are either unmistakably and appropriately pleaded or are admitted or acknowledged by the defendant, the non-production in evidence of the survey plan of such land cannot be a matter of great moment and does not dis-entitle the plaintiff from maintaining an action in respect of title, trespass or injunction over such land.
However, a survey plan becomes necessary when the following arise:
1.It is settled law that, where the identity of the land in dispute is in dispute, there is need to produce a survey plan particularly if the facts produced in evidence cannot establish with certainty, the identity of the said land.
2. Where parties file different survey plans on both side, it will be the duty of the party who disputes the identity of the land (and who wants to succeed), to file a composite plan where it becomes necessary or as the court may direct at the trial. The purpose of filing a composite plan is to fix and delimit the land in dispute
3. Where a plaintiff pleads and serves the defendant a survey plan which is subsequently admitted in evidence as exhibit and which shows the boundaries and features on the land in dispute, this will constitute sufficient proof of the boundaries and features set out in the land in dispute.
A defendant who intends to challenge or dispute such boundaries or features as shown in the survey plan must do so by specifically traversing the plaintiff’s pleading in that regard, because a mere general traverse will be insufficient.
In the event that a plaintiff tenders a survey plan of the land in dispute, and the plan is admitted without objection while the defendant fails to file a counter claim, the defendant cannot be heard to contend that the plaintiff did not prove with certainty the.
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Monday, 2 January 2017
The Relevance of a Survey Plan
Wednesday, 14 December 2016
LESSON NOTE ON USING PLANE TABLE AND ALIDADE SURVEY
METHODS OF SURVEY:
USING PLANE TABLE AND ALIDADE SURVEY
1. This is a method of survey
that allows a surveyor to plot and create an accurate scale
drawing on site. The idea is to scale down the site to a size that
fits onto the drawing board.
2. A plane table is a
drawing board which is fixed to a tripod, leveled, and orientated. An
alidade is a sighting device used to observe the salient points of the
site.
3. Have a good look at the site
before you start the survey, time should be taken to walk round
and have a good look at the site or building that you are going to record. On
a building, the obvious features that you would want to record are the
corners, door and window openings, fireplaces. More subtle features that you
would look out for are changes in wall direction, straight joints, blocked
doors or windows, crack slots, changes in the stonework, changes in floor
covering, byre drains.
STEP 1:-SELECT A SURVEY STATION
Once you have
had a good look at the site, you will select a position for your survey station
from which you have a line of site to as many of the main points as possible. It is particularly
important to be able to see all the corners and places where a feature has a change in direction. Set up the
tripod legs over your selected survey station. Prepare the drawing board; a piece of polyester drafting film is taped onto the drawing board with masking tape. The corners are taped
first, with the film pulled tight, and then the edges are taped. The board is
fixed onto the tripod.
STEP
2:- ORIENT THE DRAWING BOARD
When drawing a
building you would orientate the long side of the board so that it
is parallel to the long axis of the building. If possible, for a site plan, you would orient the board so that north is up the page. For all plans it is important to check that the whole
site is going to fit on the board at your chosen scale. A pin is positioned into the board to give a fixed point from which observations and
measurements can be taken. The pin marks the position of your survey
station on the board. Once the survey has commenced the plane table should not
be moved.
STEP
3:- CARRY OUT THE SURVEY
The alidade is
placed against the pin and used to observe in turn, selected points. Rays are
drawn on the film and measurements between the pin and the points taken with
the 30mtape. The measurement is written onto the drawn ray as a record.
Subsequently, each point is plotted along the ray at the selected scale, ' with a scale rule.
Observations and measurements are taken to as many points as required to allow
the shape to be recorded. These plotted points create an accurate framework
around which the rest of the plan can be constructed. This method is most useful for plans of single buildings or
small siteswithin a radius of 30m from the plane table.
THE 3 MAIN TYPE OF LEVELS / LEVELLING INSTRUMENT
LEVELLING INSTRUMENT
Level is an instrument used in
establishing horizontal line. it uses spirit babble tube with the construction
of telescope, you can sight or object aid also focus, line of sight is called
line of collaboration. Basically there are 3 main types of level or leveling
instrument.
Each instrument have a few basic
parts the working of which will be firmly under store. Hide are dumping level,
tilting level, automatic level. Each is used in sighting different ways.
DUMPING LEVEL
This is the most common form of
survey level and it consist of able tube attach to the telescope.
The telescope is rightly fixed to
the stage which has 3 or 4 foot screw.
The foot screw used to bring the
babble to the centre of its run and also to make axis of the babble horizontal.
If the line at collimation is parallel to the able axis then the line of
collonation is horizontal. The advantage was in the fact that when it is
leveled, you can sight all the direct – this instrument is getting out of the
………………….
TILTING LEVEL
Is an improvement of the dumping
level, instead of being tilted. When using this instrument it is only necessary
to set it roughly leveled. As babble is finally leveled for each reading by
means of adjusting screws ad thus greater accuracy is obtained. Since the babbles
axis is always mark to be right angle with the axis however the adjustment is
done before every reading.
AUTOMATIC LEVEL
Just as the name implies, it is an
automatic instrument. the instrument may be out of adjustment if the recticle
is mis-position after carrying out the task as described for titling level.
In automatic level, the horizontal
hair is brought to the correct readings by MV of recticle.
The instrument has circular spirit
babble you don’t have to set the babbles every time. It also gives direct image
instead of inverted images.
Along with any of the above 3 types
of level we can also use level staff, staff plate or cross-foot especially when
we are on soft ground.
Monday, 5 December 2016
SURVEYING EQUIPMENT AND LEVEL SET-UP
SURVEYING EQUIPMENT AND LEVEL SET-UP
 The opposite figure shows a LEICA Level packages.time you borrow a level. can be borrowed from the following persons:   There are different types (Leica, Sokkia, Wild) of levels you can borrow. The level opposite is a Leica NA720. Most level instruments have an automatic horizontal adjustment of the line of sight. Levels are supplied in a case in which the instrument can be shock proof stored. All survey levels operate in a similar way. The function and operation of levels is explained using the Leica 720 which is the most available instrument in the storerooms.
Levelling staffs (rods) and accessories    There are many types of staffs, with names that identify the form of the graduations and other characteristics. Staffs can be one piece, but most of them are sectional and adjust the length by telescoping..
The metric staff has major numbered graduations in meters and tenths of meters (there is a tiny decimal point between the numbers). Our staves have an ''E'' shape mark (or its mirror image) with horizontal spaces between them of 10 mm.
When viewed through an instrument's telescope, the observer can easily visually interpolate a 10 mm mark to a quarter of its height, giving a reading accuracy of 2.5 mm. On one side of the rod, the colours of the markings alternate between red and black with each meter of length.
The Black arrows indicates where to push to extend the staff to its full length.
Staff readings
The figure below shows three different staff readings:
It is easy to read (b) and (c) because the cross-hair is exactly on a mark division. The reading for (a) is between 1.630 and 1.640. To assess the mm reading you have to estimate where the position of the cross-hair is. For (a) the reading is 1.636. The millimeter reading is to be estimated and can very between ± 1 mm.
reading (a) is 1.636 (b) is exactly 1.500 and (c) is 1.580
Spirit & line levels
  There are a wide range of spirit levels to meet the varying requirements of specific jobs. The majority of those used on construction work are made of powder coated aluminum or die cast construction. The length varies from 800 mm to 2000 mm. Spirit levels are very handy for short distance levelling (depending on the spirit level up to 2 metres and with straight edge up to approximate 5 metres). The straight edge is used if the the points to be levelled exceed the length of the spirit level.
The line level has been designed and made with two small hooks to hold it on a line as shown in the figure above. A line level is a level designed to hang on a string line. The level must hung in the center of the string and each ''leg'' of the string line extends the levels plane.
The line level is a simple surveying instrument which can be used to lay out contours and gradients, and also to assist measuring horizontal distances at slope.
Plumb bobs
Water level
 An old device but a simple instrument for measuring the level differences of two points. This level, is illustrated in the opposite figure. The two levelling staffs are of the same length with a graduated tape attached to each stave. The tube is filled with water. The ends of the tube are fitted with rubber stoppers to prevent loss of water. The total length of tube defines the range of the instrument.Straight edge
A 'straight edge' in conjunction with a spirit level and tape measure can be used to establish a gradient. The straight edge is usually 3 to 5 metres long and set horizontally with the aid of a spirit level. This method should be used for the measurement of gradients which continue only for short distances, e.g. to calculate the horizontal distance shown in plan-views. The figure below shows how a gradient for the ground profile is found.
Distinguish between a horizontal distance and a slope distance. All distances should be measured 'horizontally'. Do not measure along slopes. Sag (tape are not supported for its length will sag under the influence of gravity) and to a lesser extent temperature may have an effect on the distance measurement also. To reduce the sag break tape measurement into shorter lengths.
  The sum of horizontal lengths (L1 & L2) equals the horizontal distance of the slope from A to C. Remember the horizontal distance is always shorter than the measurement on the slope.
For an accurate measurement, the tape should be held horizontal and straight with a specified tension applied to it.
Slopes - Gradient calculations
0.06666 × 100 = 0.06666 Percentage = 6.667% tan a = 200/3000 = 0.06666 a = 3.814°
Distance measurement methods
 For measuring a distance we use steel or fibre glass tapes as shown in the opposite figure. They are available in 30 metre and 50 metre length.
A more sophisticated method is to use the Electronic Distance Measuring (EDM).
We will not use this method. EDM devices use electromagnetic waves, infrared waves, or lasers to measure distances precisely.
Approximate (fairly accurate) distance measurement method is 'pacing' or using the 'stadia lines' on the reticle of the level
Pacing Don't try to pace out one metre with every step. Walk casually over 50 or better 100 metre counting the number of steps. Work out the length of a casual step and use this instead. The longer the walking distance the more accurate is the step measurement. Example If it takes you 65 steps to walk 50 metres; then your step is 50/65 = 0.77 metre. If you would waked 39 steps, then the distance is 39 x 0.77 = 30 m. Stadia lines The stadia lines on the reticle can be used for simple distance measurement. The distances intercepted on the vertically-held rod between two stadia hairs seen in the eyepiece gives the distance. Just multiply the difference on the rod between the top and bottom stadia lines by 100* as shown in the figure below.  In the example above the distance between the top and bottom stadia hair is 62 mm. Therefore, the distance to the staff is 62 × 100 = 6200 mm or 6,2 metres. * The 100 figure should be checked before beginning any survey by measuring the known distance with a tape.
Surveyors usually use total stations for land surveying. A total stations is a combination of an electronic theodolite (transit), and electronic distance measuring device (EDM).
Other accessories
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If you want to centre an instrument over a ground point:
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