Since 2007 Doonan has used a 12 or 13 digit “string” of characters to represent its model number. This “string” is actually a part of a smart numbering system with each position representing a specific structural feature of the trailer. The table below shows what each position of the model string represents.

1 & 2
Length		3
Width		4
Style		5
# of Axles		6
Sill Space		7
Tire Size

05 = 05’

48 = 48’

50 = 50’

53 = 53’

etc

0 = 120”

1 = 110”

2 = 102”

4 = 114”

6 = 96”

8 = 108”

A = aluminum drop deck

B = aluminum flat bed

C = aluminum double drop

D = steel drop deck

E = steel double drop deck

F = steel flat bed

G = steel tappered drop deck

H = steel narrow neck drop deck

I = steel narrow neck double drop deck

J = steel narrow neck 4-beam

K = 4-beam

L = CP trailer

M = combo drop deck

N = combo double drop deck

O = combo flat bed

P = combo tappered drop deck

Q = lowboy RGN full width neck

R = lowboy RGN narrow neck

S = lowboy fixed neck full width neck

T = lowboy fixed neck narrow neck

U = RGN 4-beam

V = Sissor Neck

Z = misc

1 = Platinum dropdeck (43” ctrs)

2 = Platinum doubledrop (43” ctrs)

3 = Platinum flatbed (43” ctrs)

4 = Platinum tapered dropdeck (43” ctrs)

9 = Flip Axle

A = 1

B= 2

C = 3

D = 4

E = 5

F = 6

G = 7

H = 8

Z = misc

A = 9”

*B = 12”

*C = 14”

D = 15”

*E = 16”

F = coil area

K = 9” Alum

L = 12” Alum

M = 14” Alum

N = 15” Alum

O = 16” Alum

**P = Steel Sills

**Q = Alum Sills

Z = misc

A = 285/75R24.5

B = 11R24.5

C = 245/70R19.5

D = 265/70R19.5

E = 275/80R24.5

F = 235/75R17.5

G = 245/70R17.5

H = 11R22.5

I = 255/70R22.5

J = 275/70R22.5

K = 275/80R22.5

L = 295/75R22.5

M = 315/80R22.5

N = 445/50R22.5

O = 445/65R22.5

P = 445/55R22.5

Z = misc

8
Top Deck		9
GN Drop		10
Beam Size		11
Spread		12
Overhang		13
Extras

A = 8‘’

B = 9’’

C = 10’’

D = 11‘’

E = 12’’

F = 13‘’

G = 14‘’

H = 15‘’

I = 16’’

L = 19’

T = flat bed

Z = misc

A = 15”

B = 18”

C = 20”

D = 22”

E = 23”

F = 24”

G = 25”

H = 26”

I = 28”

J = 31”

K = 32”

L = 33”

M = 36”

N = 38”

O = 40”

P = 41”

Q = 42”

R = 29”

S = 30”

T = flat bed

Z = misc

A = 5” Standard Alum Beam

B = 5” Heavy Duty Alum Beam

C = 5” Super Duty Alum Beam

D = 3/8” Flange

E = 1/2” Flange

F = 5/8” Flange

G = 3/4” Flange

H = 1” Flange

I = 3/8” & 1/2” Flange

J = 1/2” & 5/8” Flange

K = 5/8” & 3/4” Flange

L = 1/2” & 3/4” Flange

M = 6” Standard Alum Beam

N = 6” HD Alum Bea

O = 6” SHD Alum Bea

Z = misc

A = 49”

B = 50”

C = 54”

D = 55”

E = 60”

F = 61”

G = 72”

H = 96”

I = 108”

J = 120”

K = 122”

*L = CAL/CN

*M = 61/122 rear slide

*N = 60/120 rear slide

*O = 61/122 front slide

*P = 60/120 front slide

*S = slider

Z = misc

A = 28”

B = 30”

C = 36”

D = 38”

E = 39”

F = 42”

G = 44”

H = 48”

I = 52”

J = 57”

K = 60”

L = 66”

M = 72”

N = 70”

O = 75”

P = 88”

Q = 90”

R = 69”

S = 61”

U = 118”

Z = misc

B = boat trailer

C = coil kit

D = dovetail

E = extendable tailroller

F = flip neck

G = B-train lead

H = shallow neck

J = Tank Hauler

K = Mini Double Drop

O = Open Wheel Wells

P = side pullouts

S = skid

T = tail roller

W = wheel wells in frame

X = extendable

Z = misc

Sill Space* When used with Q, R, S, T, X or Y styles this number refers to beam depth not sill space. Sill Space**Use P & Q to distinguish between a Black Gold & Platinum Flip Axle. Spread* When model is Slider, use rear most setting for overhang. Ex: 61/122” sp, 44/105” oh = SG. Spread** When model is a slider that is dual position to be legal in Canada and California.

Below is an example of an actual trailer to illustrate what each position of the model number represents. This is a 53’ Platinum drop deck model number 532MCMIDCEEJ.

53 – 2 – M – C -M – I – D – C – E – E – J
1 & 2 Length 53 53’ Long
3 Width 2 102” Wide
4 Style M Combo drop deck
5 # of Axles C 3 axles
6 Sill Space M 14” aluminum sill spacing
7 Tire Size I 255/70R22.5 tires
8 Top Deck D 11’ upper deck length
9 GN Drop C 20” gooseneck drop
10 Beam Size E 1/2” top & bottom flange
11 Spread E 60” spread
12 Overhang J 57” overhang
13 Extras